‌Iglared at the Astrophage. “Why the heck do you go to Venus?”‌

The microscope view was displayed on the big wall-mounted monitor.

Each of the three little cells were a foot across at this magnification. I watched for any clues to their motivations, but Larry, Curly, and Moe offered no answer.

I’d named them, of course. It’s a teacher thing.

“What’s so special about Venus? And how do you even find it?” I crossed my arms. If Astrophage understood body language, they’d know I wasn’t messing around. “It takes a room full of really smart people at NASA to work out how to get to Venus. And you do it as a single-celled organism with no brain.”

It had been two days since Stratt left me alone with the lab. The army guys were still at the doors. One was named Steve. Friendly guy. The other never spoke to me.

I ran my hands through my greasy hair (I’d neglected to shower that morning). At least I didn’t have to wear the hazmat suit anymore. Scientists in Nairobi had taken a chance with one of their Astrophage and exposed it to Earth atmosphere to see what happened. It was unaffected. So, thanks to them, labs all over the world could breathe a sigh of relief and stop working in argon-filled rooms.

I glanced at the pile of papers on a desk. The scientific community had moved into overdrive in a very unscientific way. Gone were the days of careful peer review and published articles. Astrophage research was a free- for-all where researchers posted their findings immediately and without proof. It led to misunderstandings and mistakes, but we just didn’t have time to do things the right way.

Stratt kept me in the loop on most stuff. Not everything, I was sure. Who knows what other weird things she was up to. She seemed to have authority everywhere.

A Belgian research team was able to prove that Astrophage reacts to magnetic fields, but only sometimes. Other times, it seems to ignore magnetic fields entirely, no matter how powerful. Still, the Belgians were able to (very inconsistently) steer Astrophage around by putting it in a magnetic field and changing the field’s orientation. Was that useful? No idea. At this point the world was just collecting data.

A researcher in Paraguay showed that ants will get disoriented when they’re within a few centimeters of Astrophage. Was that useful? Okay, that one probably wasn’t useful. But it was interesting.

Most notably, a group in Perth sacrificed one of their Astrophage and did a detailed analysis on all the organelles inside. They found DNA and mitochondria. In any other situation, this would have been the most important discovery of the century. Alien life—indisputably alien—had DNA and mitochondria!

And…grumble…a bunch of water…

Point is: The inside of an Astrophage wasn’t much different from the inside of any single-celled organism you’d find on Earth. It used ATP, RNA transcription, and a whole host of other extremely familiar things. Some researchers speculated that it originated on Earth. Others postulated this specific set of molecules was the only way for life to occur and Astrophage evolved it independently. And a smaller, vocal faction suggested life might not have evolved on Earth at all, and that Astrophage and terrestrial life have a common ancestor.

“You know,” I told the Astrophage, “if you boys weren’t threatening all life on my planet, you’d be pretty awesome. You have mysteries within mysteries.”

I leaned against a table. “You have mitochondria. Okay, so that means you use ATP as your energy storage, just like we do. But the light you use to move around requires waaaay more energy than your ATP can hold. So you have another energy-storage pathway. One we don’t understand.”

One of the Astrophage on-screen darted slightly to the left. It was pretty common. Once in a while, for no real reason, they’d just wiggle.

“What makes you move? Why move? And how does this random jerky motion get you from the sun to Venus? And why do you go to Venus at all?!”

Lots of people were working on the internals of Astrophage. Trying to figure out what made it tick. Analyzing its DNA. Good for them. I wanted to know the basic life-cycle. That was my goal.

Single-celled organisms don’t just store buttloads of energy and fly through space for no reason. There had to be something Astrophage needed from Venus or it would just stay on the sun. And it needed something from the sun, too, or it would stay on Venus.

The sun part was pretty easy: It was there for the energy. Same reason plants grew leaves. Got to get that sweet, sweet energy if you’re going to be a life-form. Makes perfect sense. So what about Venus?

I picked up a pen and fidgeted with it as I thought.

“According to the Indian Space Research Organization, you guys get going up to 0.92 times the speed of light.” I pointed at them. “Didn’t know we could do that, did ya? Figure out your velocity? They used Doppler-shift analysis of the light you emit to work it out. And because of that, they also know you’re going both directions: to and from Venus.”

I frowned. “But if you hit an atmosphere at that speed you should die. So why don’t you?”

I rapped my forehead with a knuckle. “Because you can handle any amount of heat. Right. So you blast into the atmosphere, but you don’t get any hotter. Okay, but you’d have to at least slow down. So you’d just be in the upper atmosphere of Venus. Then you…what? Turn around and go back to the sun? Why?”

I stared at the screen for a solid ten minutes, lost in thought. “All right, enough of this. I want to know how you find Venus.”

I went to the local hardware store and bought a bunch of two-by-fours, three-quarter-inch plywood, power tools, and other stuff I’d need. Steve the army guy helped me carry a lot of it in. Jerk army guy did nothing.

Over the next six hours, I built a lightproof closet with a shelf in it. It was just big enough for me to get in and out. I set the microscope on the shelf.

The “door” was a plywood panel that I could remove with screws.

I ran power and video lines into the closet through a little hole that I plugged up with putty to make sure no light could get in through there either. I set my IR camera up on the microscope and sealed up the closet.

Out in the lab, the monitor showed the infrared light the camera saw. It was basically a frequency shift. Very low bands of IR would show up as red. Higher-energy bands would be orange, yellow, and so on up the rainbow. I could see the Astrophage cells as little red blobs, which was expected. At their constant temperature of 96.415 degrees Celsius they would naturally emit an IR wavelength of 7.8 microns or so—the low end of what I’d set the camera to look for. It was good confirmation that the setup was working.

But I didn’t care about that dark-red color. I wanted to see a bright-yellow flash. That would be the Petrova frequency that Astrophage spit out to move around. If any of my Astrophages moved even the tiniest amount, I’d see a very obvious yellow flash.

But it never came. Nothing happened. Nothing at all. Usually, I’d see a jerky motion from at least one of them every few seconds. But now there was nothing.

“So,” I said. “You little brats have settled down, eh?”

Light. Whatever their navigation system was, it was based on light. I suspected that would be the case. What else could you use in space? There’s no sound. No smell. It would have to be light, gravity, or electromagnetism. And light’s the easiest of those three to detect. At least, as far as evolution is concerned.

For my next experiment, I taped a little white LED and a watch battery together. Of course, I wired it backward at first and the LED didn’t light up. That’s pretty much a rule in electronics: You never get diodes right on the first try. Anyway, I rewired it correctly and the LED lit up. I taped the whole contraption to the inside wall of the closet. I made sure to position it so the Astrophage on the sample slide would have a direct line of sight on it. Then I sealed everything up again.

Now, from the Astrophage’s point of view, there was a lot of black nothingness and one shining spot of white. That’s kind of what Venus might look like if you were out in space and looking directly away from the sun.

They didn’t budge. No hint of motion at all. “Hmph,” I said.

To be fair, it wasn’t likely to work. If you were at the sun, looking away from it for the brightest splotch of light you could see, you’d probably zero in on Mercury, not Venus. Mercury is smaller than Venus, but it’s a lot closer so you’d see more light.

“Why Venus?” I mused. But then I thought of a better question. “How do you guys identify Venus?”

Why did they move randomly? My theory: By pure chance, every few seconds or so, an Astrophage thought it had spotted Venus. So it thrusted in that direction. But then the moment passed, so it stopped thrusting.

The key had to be frequencies of light. My boys didn’t wiggle at all in darkness. But it wasn’t just about the sheer volume of light, or they would have gone for the LED. It had to be something about the frequency of the light.

Planets don’t just reflect light. They also emit it. Everything emits light. The temperature of the object defines the wavelength of light emitted. Planets are no exception. So maybe Astrophage looked for Venus’s IR signature. It wouldn’t be as bright as Mercury’s, but it would be distinct—a different “color.”

A little googling told me Venus’s average temperature was 462 degrees Celsius.

I had a whole drawer full of replacement bulbs for microscopes and other lab stuff. I grabbed one and hooked it up to a variable power supply. Incandescent bulbs work by getting the filament so hot it emits visible light. That happens around 2,500 degrees Celsius. I didn’t need anything so dramatic. I just needed a measly 462 degrees. I adjusted power going through the bulb up and down, watching with an IR camera, until I got exactly the light frequency I wanted.

I moved the whole contraption into my test closet, watched the monitor with my boys on it, and turned on the artificial Venus.

Nothing. Absolutely no movement from the little jerks. “What do you want from me?!” I demanded.

I pulled my goggles off and threw them to the ground. I drummed my fingers on the table. “If I were an astronomer, and someone showed me a blob of light, how would I know if it’s Venus?”

I answered myself. “I’d look for that IR signature! But that’s not what Astrophage does. Okay, someone shows me a blob of light and says I’m not allowed to use emitted IR to work out the temperature of the body. How else could I find out if it’s Venus?”

Spectroscopy. Look for carbon dioxide.

I raised an eyebrow as the idea came to me.

When light hits gas molecules, the electrons get all worked up. Then they calm down and re-emit the energy as light. But the frequency of the photons they emit is very specific to the molecules involved. Astronomers used this for decades to know what gases are out there far, far away. That’s what spectroscopy is all about.

Venus’s atmosphere is ninety times Earth’s pressure and almost entirely carbon dioxide. Its spectroscopy signature of CO2 would be overwhelmingly strong. Mercury had no carbon dioxide at all, so the nearest competitor would

be Earth. But we had a minuscule CO2 signature compared to Venus. Maybe

Astrophage used emission spectra to find Venus?

New plan!

The lab had a seemingly infinite supply of light filters. Pick a frequency, and there’s a filter for it. I looked up the spectral signature of carbon dioxide

—the peak wavelengths were 4.26 microns and 18.31 microns.

I found the appropriate filters and built a little box for them. Inside I put a small white lightbulb. Now I had a box that would emit the spectral signature of carbon dioxide.

I put it in the test closet and went out to watch the monitor. Larry, Curly, and Moe hung out on their slide, just like they had all day long.

I flicked on the light box and watched for any reaction.

The Astrophage left. They didn’t just meander toward the light. They were gone. Absolutely gone.

“Um…”

I had been recording the camera input, of course. I ran it back to watch frame by frame. Between two frames they simply disappeared.

“Um!”

Good news: Astrophage were attracted to carbon dioxide’s spectral signature!

Bad news: My three irreplaceable, 10-micron-wide Astrophage had launched off somewhere—maybe at velocities approaching the speed of light

—and I had no idea where they went. “Craaaaaap.”

—

Midnight. Darkness everywhere. The army guys changed shift to two guys I didn’t know. I missed Steve.

I had aluminum foil and duct tape up over every window of the lab. I sealed the cracks around the entrances and exits with electrical tape. I turned off every piece of equipment that had a readout or LED of any kind. I put my watch in a drawer because it had glow-in-the-dark paint on the hands.

I let my eyes adjust to the total darkness. If I saw so much as a single shape that wasn’t my imagination, I sought out the light leak and put tape over it. Finally, I reached a level of darkness so intense I couldn’t see anything. Opening or closing my eyes had no effect at all.

The next step was my newly invented IR goggles.

The lab had many things, but infrared goggles were not among them. I’d considered asking Steve the army guy if he could score some. I probably could have called Stratt and she would have had the president of Peru personally deliver them or something. But this was faster.

The “goggles” were just the LCD output screen of my IR camera with a bunch of tape around them. I pressed them to my face and added more tape. Then more and more and more. I’m sure I looked ridiculous. But whatever.

I fired up the camera and looked around the lab. Plenty of heat signatures. The walls were still warm from sunlight earlier that day, everything electrical had a glow, and my body shined like a beacon. I adjusted the frequency range to look for much hotter things. Specifically, things over 90 degrees Celsius.

I crawled into my makeshift microscope closet and looked at the light box I’d used for the CO2 spectral emission.

Astrophage are only 10 microns across. No chance I’d see something so small with the camera (or with my eyes, for that matter). But my little aliens are very hot, and they stay hot. So, if they’re not moving, they will have spent the last six hours or so slowly heating up their surroundings. That was the hope.

It panned out. I immediately saw a circle of light on one of the plastic light filters.

“Oh thank God,” I gasped.

It was very faint but it was there. The spot was about 3 millimeters across and grew fainter and colder away from the center. The little fella had been heating up the plastic for hours. I scanned back and forth across the two plastic squares. I quickly found a second spot.

My experiment worked way better than I expected. They saw what they thought was Venus and beelined for it. When they hit the light filters, they couldn’t go any farther. They probably kept pushing until I turned off the light.

Anyway, if I could just confirm that all three Astrophage were present, I could bag the filters, then spend however long I needed to find and harvest the boys from them with a microscope and pipette.

And there it was. The third Astrophage.

“The gang’s all here!” I said. I reached into my pocket for a sample bag and got ready to very carefully pull the filter off the light box. That’s when I saw the fourth Astrophage.

Just…minding its own business. A fourth cell. It was right in the same general cluster as the first three, on the filters.

“Holy…”

I’d been staring at these guys for a week. There’s no way I would have missed one. There could only be one explanation: One of the Astrophage divided. I’d accidentally made the Astrophage reproduce.

I stared at that fourth spot of light for a full minute, taking in the magnitude of what had just happened. Breeding Astrophage meant we would

have an unlimited supply for study. Kill them, poke them, take them apart, do whatever we wanted. This was a game changer.

“Hello, Shemp,” I said.

—

I spent the next two days obsessively studying this new behavior. I didn’t even go home—I just slept in the lab.

Steve the army guy brought me breakfast. Great guy.

I should have shared all my findings with the rest of the science community, but I wanted to be sure. Peer review may have fallen by the wayside, but at least I could self-review. Better than nothing.

The first thing that bothered me: CO2 spectral emissions are 4.26 and

18.31 microns. But Astrophage are only 10 microns across, so it couldn’t really interact with light that had a larger wavelength. How could it even see the 18.31 micron band?

I repeated my earlier spectral experiment with just the 18.31 micron filter and got a result I didn’t expect. Strange things happened.

First off, two of the Astrophage whipped over to the filter. They saw the light and went right for it. But how? It should be impossible for Astrophage to interact with a wavelength that big. I mean…literally impossible!

Light is a funny thing. Its wavelength defines what it can and can’t interact with. Anything smaller than the wavelength is functionally nonexistent to that photon. That’s why there’s a mesh over the window of a microwave. The holes in the mesh are too small for microwaves to pass through. But visible light, with a much shorter wavelength, can go through freely. So you get to watch your food cook without melting your face off.

Astrophage is smaller than 18.31 microns but somehow still absorbs light at that frequency. How?

But that’s not even the strangest thing that happened. Yes, two of them took off for the filter, but the other two stayed put. They didn’t seem to care. They just hung out on the slide. Maybe they didn’t interact with the larger wavelength?

So I did one more experiment. I shined the 4.26 micron light at them again. And I got the same results. The same two went right for the filter as before, and the other two just didn’t care.

And there it was. I couldn’t be 100 percent certain, but I was pretty sure I’d just discovered the whole Astrophage life-cycle. It clicked in my mind like puzzle pieces finally fitting together.

The two holdouts didn’t want to go to Venus anymore. They wanted to go back to the sun. Why? Because one of them just divided and created the other.

Astrophage hang out on the surface of the sun gathering energy via heat. They store it internally in some way no one understands. Then, when they have enough, they migrate to Venus to breed, using that stored energy to fly through space using infrared light as a propellant. Lots of species migrate to breed. Why would Astrophage be any different?

The Aussies already worked out that the inside of Astrophage wasn’t much different from Earth life. It needed carbon and oxygen to make the complex proteins required for DNA, mitochondria, and all the other fun stuff found in cells. There’s plenty of hydrogen on the sun. But the other elements just aren’t present. So Astrophage migrates to the nearest supply of carbon dioxide: Venus.

First, it follows magnetic field lines and goes straight away from the sun’s North Pole. It has to do that, or the light from the sun would be too blinding to find Venus. And going straight up from the pole means the Astrophage will have a full view of Venus’s entire orbital path—no portion of it occluded by the sun.

Ah, and that’s why Astrophage is so inconsistent on reacting to magnetic fields. It only cares about them at the very beginning of its journey and at no other time.

Then it looks for Venus’s massive carbon dioxide spectral signature. Well, not really “looks for.” It’s probably more a simple stimulus-response thing initiated by the 4.26 and 18.31 micron light bands. Anyway, once it “sees” Venus, it goes straight to it. The path it takes—straight away from the solar pole, then sharply turning toward Venus—that’s the Petrova line.

Our heroic Astrophage reaches the upper atmosphere of Venus, collects the CO2 it needs, and can finally reproduce. After that, both parent and child return to the sun and the cycle begins anew.

It’s simple, really. Get energy, get resources, and make copies. It’s the same thing all life on Earth does.

And that was why two of my little Stooges didn’t walk toward the light.

So how does Astrophage find the sun? My guess: Look for the extremely bright thing and head that way.

I separated Moe and Shemp (the sun-seekers) from Larry and Curly (the Venus-seekers). I put Larry and Curly on a different slide and put it in a light- sealed sample container. Then I set up an experiment in the dark closet for Moe and Shemp. This time, I put a bright incandescent bulb in there and turned it on. I expected them to head right toward it, but no dice. They didn’t budge. Probably not bright enough.

I went to a photography store downtown (San Francisco has a lot of photography enthusiasts) and bought the largest, brightest, most powerful flash I could find. I replaced the lightbulb with the flash and did the experiment again.

Moe and Shemp took the bait!

I had to sit down and take a breath. I should have taken a nap—I hadn’t slept in thirty-six hours. But this was too exciting. I pulled out my cell phone and dialed Stratt’s number. She answered halfway through the first ring.

“Dr. Grace,” she said. “Find something?”

“Yeah,” I said. “I figured out how Astrophage reproduce and managed to make it happen.”

Silence for a second. “You successfully bred Astrophage?” “Yes.”

“Nondestructively?” she asked.

“I had three cells. I now have four. They’re all alive and well.” Silence for another second. “Stay there.”

She hung up.

“Huh,” I said. I put the phone back in my lab coat. “Guess she’s on her way.”

Steve the army guy burst into the lab. “Dr. Grace?!” “Wha…uh, yeah?”

“Please come with me.”

“Okay,” I said. “Let me just get my Astrophage samples put away—” “There are lab techs on the way to deal with all that. You have to come

with me now.”

“O-Okay…”

—

The next twelve hours were…unique.

Steve the army guy drove me to a high school football field where a U.S. Marine Corps helicopter had already landed. Without words, they hustled me into the chopper and up we went into the sky. I tried not to look down.

The chopper took me to Travis Air Force Base, about 60 miles north of the city. Did the marines often land at air force bases? I don’t know much about the military, but that seemed odd. It also seemed a bit extreme to send in the marines just to keep me from driving through a couple of hours of traffic, but okay.

There was a jeep waiting for me on the tarmac where the helicopter landed, with an air force guy standing next to it. He introduced himself, I swear he did, but I don’t remember his name.

He drove me across the tarmac to a waiting jet. No, not a passenger jet. And not a Learjet or anything like that. This was a fighter jet. I don’t know what kind. Like I said, I don’t know military stuff.

My guide hustled me up a ladder and into the seat behind the pilot. He gave me a pill and a little paper cup of water. “Take this.”

“What is it?”

“It’ll keep you from puking all over our nice, clean cockpit.” “Okay.”

I swallowed the pill. “And it’ll help you sleep.” “What?”

Away he went, and the ground crew pulled away the ladder. The pilot didn’t say a word to me. Ten minutes later, we took off like a bat out of hell. I’d never felt acceleration like that in my life. The pill did its job. I definitely would have puked.

“Where are we going?” I asked through the headset. “I’m sorry, sir. I’m not allowed to speak to you.” “This is going to be a boring trip, then.”

“They usually are,” he said.

I don’t know exactly when I fell asleep but it was within minutes of taking off. Thirty-six hours of mad science plus whatever was in that pill put me right into dreamland regardless of the ridiculous jet-engine noise surrounding me.

I awoke in darkness to a jolt. We’d landed. “Welcome to Hawaii, sir,” said the pilot. “Hawaii? Why am I in Hawaii?”

“I wasn’t given that information.”

The jet taxied onto some side runway or whatever and a ground crew brought a ladder. I hadn’t gotten halfway down the ladder yet when I heard “Dr. Grace? This way, please!”

It was a man in a U.S. Navy uniform. “Where the hell am I?!” I demanded.

“Naval Station Pearl Harbor,” said the officer. “But not for long. Please follow me.”

“Sure. Why not?”

They put me in another jet with another non-talkative pilot. The only difference was that this time it was a navy jet instead of an air force jet.

We flew for a long time. I lost track of the hours. Keeping track was meaningless anyway. I didn’t know how long we’d be in the air. Finally, I kid you not, we landed on an honest-to-God aircraft carrier.

Next thing I knew, I was on the flight deck looking like an idiot. They gave me earmuffs and a coat and shuffled me over to a helipad. A navy chopper was waiting for me.

“Will this trip…end? Like…ever?!” I asked.

They ignored me and got me strapped in. The chopper took off immediately. This time, the flight wasn’t nearly so long. Just an hour or so.

“This should be interesting,” said the pilot. It was the only thing he’d said the whole flight.

We descended and the landing gear deployed. Below us was another aircraft carrier. I squinted at it. Something looked different. What was it…oh, right. It had a big Chinese flag flying over it.

“Is that a Chinese aircraft carrier?!” I asked. “Yes, sir.”

“Are we, a U.S. Navy helicopter, going to land on that Chinese aircraft carrier?”

“Yes, sir.”

“I see.”

We landed on the carrier’s helipad and a bunch of Chinese Navy guys watched us with interest. There would be no post-flight servicing of this chopper. My pilot leered through the windows at them and they leered right back.

As soon as I stepped out, he took off again. I was in China’s hands now.

A navy man came forward and gestured for me to follow him. I don’t think anyone spoke English, but I got the general idea. He led me to a door in the tower structure and we went inside. We wound through passageways, stairwells, and rooms I didn’t even understand the purpose of. All the while, Chinese sailors watched me with curiosity.

Finally, he stopped at a door with Chinese characters on it. He opened the door and pointed inside. I walked in and he slammed the door behind me. So much for my guide.

I think it was an officer’s conference room. At least, that was my assumption based on the big table with fifteen people sitting at it. They all turned their heads to look up at me. Some were white, some were black, some were Asian. Some wore lab coats. Others wore suits.

Stratt, of course, sat at the head of the table. “Dr. Grace. How was your trip?”

“How was my trip?” I said. “I got dragged across the gosh-darned world without any notice—”

She held up her hand. “It was just a pleasantry, Dr. Grace. I don’t actually care how your trip was.” She stood and addressed the room. “Ladies and gentlemen, this is Dr. Ryland Grace from the United States. He figured out how to breed Astrophage.”

Gasps came from around the table. One man shot to his feet and spoke with a thick German accent. “Are you serious? Stratt, warum haben sie—?”

“Nur Englisch,” Stratt interrupted.

“Why are we only hearing of this now?” the German demanded.

“I wanted to confirm it first. While Dr. Grace was en route, I had technicians pack up his lab. They collected four live Astrophage from his lab. I only left him three.”

An elderly man in a lab coat spoke Japanese in a calm, soothing voice. Next to him, a younger Japanese man in a charcoal suit translated. “Dr. Matsuka would like to respectfully request a detailed description of the process.”

Stratt stepped aside and gestured to her chair. “Doctor, have a seat and lay it out for us.”

“Hold on,” I said. “Who are these people? Why am I on a Chinese aircraft carrier? And have you ever heard of Skype?!”

“This is an international body of high-level scientists and political operatives that I have assembled to spearhead Project Hail Mary.”

“What’s that?”

“That would take a while to explain. Everyone here is eager to hear about your Astrophage findings. Let’s start with that.”

I shuffled to the front of the room and sat awkwardly at the head of the table. All eyes turned to me.

So I told them. I told them all about the wooden closet experiments. I explained all my tests, what I did for each one, and how I did them. Then I explained my conclusions: I told them my hypothesis about the Astrophage life-cycle, how it works, and why. There were a few questions from the

assembled scientists and politicos, but mostly they just listened and took notes. Several had translators whispering in their ear during the process.

“So…yeah,” I said. “That’s pretty much everything. I mean—it’s not rigorously tested yet but it seems pretty simple.”

German Guy raised his hand. “Would it be possible to breed Astrophage on a large scale?”

Everyone leaned forward a little. Apparently this was a pretty important question and it was on everyone’s mind. I was taken aback by the sudden intensity of the room.

Even Stratt seemed unusually interested. “Well?” she said. “Please answer Minister Voigt.”

“Sure,” I said. “I mean…why not?” “How would you do it?” asked Stratt.

“I guess I’d make a big elbow-shaped ceramic pipe and fill it with carbon dioxide. Make one end of it as hot as you can get it and have a bright light there. Wrap a magnetic coil around it to simulate the magnetic field of the sun. Put an IR light emitter at the other end of the elbow and have it emit light at 4.26 and 18.31 microns. Make the inside of the pipe as black as you can. That should do it.”

“How does that ‘do it’?” she said.

I shrugged. “The Astrophage will gather energy at the ‘sun’ side and when they’re ready to breed, they’ll follow that magnetic field to the pipe’s elbow. They’ll see the IR light at the other end and head toward it. Seeing that light and being exposed to carbon dioxide makes them breed. Then the parent and daughter cells will go back to the sun side. Simple enough.”

A political-looking man raised his hand and spoke with some kind of African accent. “How much Astrophage could be made this way? How fast is the process?”

“It would have a doubling time,” I said. “Like algae or bacteria. I don’t know how long it is, but considering the sun is getting dim it must be pretty quick.”

A woman in a lab coat had been on her phone. She set it down, then spoke with a thick Chinese accent. “Our scientists have reproduced your results.”

Minister Voigt scowled at her. “How did you even know his process? He just told us!”

“Spies, presumably,” said Stratt.

The German huffed. “How dare you circumvent us with—”

“Shush,” said Stratt. “We’re past all that. Ms. Xi, do you have any additional information to share?”

“Yes,” she said. “We estimate the doubling time to be just over eight days, under optimal conditions.”

“What does that mean?” the African diplomat said. “How much can we make?”

“Well.” I launched my phone’s calculator app and tapped a few buttons. “If you started with the one hundred and fifty Astrophage we have, and bred them for a year, at the end of it you’d have…about 173,000 kilograms of Astrophage.”

“And would this Astrophage be at maximum energy density? Would it all be ready to reproduce?”

“So you want…I guess you’d call it ‘enriched’ Astrophage?”

“Yes,” he said. “That’s a perfect word for it. We want Astrophage that is holding as much energy as it can.”

“Uh…I guess that could be arranged,” I said. “First, breed up the number of Astrophage you want, then expose them to lots of heat energy but don’t let them see any carbon dioxide spectral lines. They’ll collect energy and just sort of sit there waiting until they can see somewhere to get CO2.”

“What if we needed two million kilograms of enriched Astrophage?” said the diplomat.

“It’s doubling every eight days,” I said. “Two million kilos would be another four doublings or so. So, one month longer.”

A woman leaned forward on the table, her fingers steepled. “We might just have a chance.” She had an American accent.

“An outside chance,” said Voigt.

“There is hope,” said the Japanese translator—presumably speaking for Dr. Matsuka.

“We need to talk amongst ourselves,” said Stratt. “Go get some rest. The sailor outside will show you to a bunk.”

“But I want to know about Project Hail Mary!” “Oh, you will. Believe me.”

—

I slept for fourteen hours.

Aircraft carriers are awesome in many ways, but they aren’t five-star hotels. The Chinese had given me a clean, comfy cot in an officer’s bunkroom. I had no complaints. I could have slept on the flight deck I was so tired.

I felt something weird on my forehead when I woke up. I reached up and it was a Post-it note. Someone put a Post-it on my head while I slept. I pulled it off and read it:

Clean clothes and toiletries in the duffel under your bunk. Show this note to any sailor when you’ve cleaned up: 请带我去甲板7的官员会议室

—Stratt

“She is such a pain in my butt…” I mumbled.

I stumbled out of my cot. A few officers gave me passing glances but otherwise ignored me. I found the duffel and, as promised, there were clothes and dental-hygiene stuff and soap. I glanced around the bunkroom and saw through a doorway into a locker room.

I used the bathroom (or “head” I guess, because I was on a ship). Then I took a shower with three other guys. I dried off and put on the jumpsuit onesie Stratt had left me. It was bright yellow, had Chinese writing along the back, and a big red stripe down the left leg of the pants. My guess was to make sure everyone knew I was a foreign civilian and not allowed in certain places.

I flagged down a passing sailor and showed him the note. He nodded and gestured for me to follow. He led me through a maze of twisty little passages, all alike, until we arrived back at the room I’d been in the previous day.

I stepped in to see Stratt and some of her…teammates? A subset of the previous day’s gang. Just Minister Voigt, the Chinese scientist—I think her name was Xi—and a guy in a Russian military uniform. The Russian had been there the previous day but hadn’t said anything. They all looked deep in concentration and the table was littered with paper. They mumbled to one another here and there. I didn’t know the exact relationships going on, but Stratt was definitely at the head of the table.

She looked up as I entered.

“Ah. Dr. Grace. You look refreshed.” She gestured to her left. “There’s food on the credenza.”

And there was! Rice, steamed buns, deep-fried dough sticks, and an urn of coffee. I rushed over and helped myself. I was hungry as heck.

I sat at the conference table with a full plate and cup of coffee.

“So,” I said with a mouth full of rice. “You gonna tell me why we’re on a Chinese aircraft carrier?”

“I needed an aircraft carrier. The Chinese gave me one. Well, they lent it to me.”

I slurped my coffee. “There was a time when something like that would surprise me. But…you know…not anymore.”

“Commercial air travel takes too long and is prone to delays,” she said. “Military aircraft work on whatever schedule they want and travel supersonically. I need to be able to get experts from anywhere on Earth in the same room with no delays.”

“Ms. Stratt can be extremely persuasive,” said Minister Voigt.

I shoveled more food into my mouth. “Blame whoever gave her all that authority,” I said.

Voigt chuckled. “I was part of that decision, actually. I am Germany’s minister of foreign affairs. The equivalent of your country’s secretary of state.”

I paused my chewing. “Wow,” I managed to say. I gulped down the mouthful. “You’re the most high-ranking person I’ve ever met.”

“No, I’m not.” He pointed to Stratt.

She put a piece of paper in front of me. “This is what led to the Hail Mary Project.”

“You’re showing him?” Voigt said. “Now? Without getting him a clearance

—”

Stratt put her hand on my shoulder. “Dr. Ryland Grace, I hereby grant you top-secret clearance to all information pertaining to Project Hail Mary.”

“That’s not what I meant,” Voigt said. “There are processes and background checks to—”

“No time,” Stratt said. “No time for any of that stuff. That’s why you put me in charge. Speed.”

She turned toward me and tapped the paper: “These are readings from amateur astronomers all over the world. They show something very important.”

The page had columns of numbers. I noticed the column titles: “Alpha Centauri,” “Sirius,” “Luyten 726-8,” and so on.

“Stars?” I said. “These are all stars in our local cluster. And wait—did you say amateur astronomers? If you can tell the German minister of foreign affairs what to do, why don’t you have professional astronomers working for you?”

“I do,” Stratt said. “But this is historical data collected over the past several years. Professional astronomers don’t study local stars. They look at faraway things. It’s the amateurs who log data on local stuff. Like train spotters. Hobbyists in their backyards. Some of them with tens of thousands of dollars’ worth of equipment.”

I picked up the paper. “Okay, so what am I looking at?”

“Luminosity readings. Normalized across thousands of amateur-generated data sets and corrected for known weather and visibility conditions. Supercomputers were involved. The point is this: Our sun is not the only star that’s getting dimmer.”

“Really?” I said. “Ohhh! That makes perfect sense! Astrophage can travel at 0.92 times the speed of light. If it can go dormant and stay alive long enough, it could infect nearby stars. It spores! Just like mold! It spreads from star to star.”

“That’s our theory, yes,” said Stratt. “This data goes back decades. It’s not deeply reliable but the trends are there. The NSA back-calculated that—”

“Wait. NSA? The U.S. National Security Agency?”

“They have some of the best supercomputers in the world. I needed their supercomputers and engineers to try all kinds of scenarios and propagation models for how Astrophage could get around in the galaxy. Back to the point: These local stars have been dimming for decades. And the rate of dimming increases exponentially—just like we’re seeing with the sun.”

She handed me another piece of paper. It had a bunch of dots connected by lines. Above each dot was a star name. “Owing to the speed of light, our observations of the dimming had to be adjusted for the distances of the stars and whatnot, but there’s a clear pattern of ‘infection’ from star to star. We know when each star was infected and by which infected star. Our sun was infected by a star called WISE 0855–0714. That star was infected by Sirius, which was infected by Epsilon Eridani. From there, the trail goes cold.”

I peered at the chart. “Huh. WISE 0855–0714 also infected Wolf 359, Lalande 21185, and Ross 128.”

“Yes, every star eventually infects all of its neighbors. Judging from our data, we think Astrophage has a maximum range of just under eight light- years. Any star within that range of an infected star will eventually be infected.”

I looked at the data. “Why eight light-years? Why not more? Or less?” “Our best guess is the Astrophage can only survive so long without a star

and it can coast about eight light-years in that time.”

“That’s sensible, from an evolution point of view,” I said. “Most stars have another star within eight light-years, so that’s as far as Astrophage had to evolve to travel while sporing.”

“Probably,” Stratt said.

“Nobody noticed those stars getting dimmer?” I said.

“They only get to about ten percent dimmer before they stop dimming. We don’t know why. It’s not obvious to the naked eye, but—”

“But if our sun dims by ten percent, we’re all dead,” I said. “Pretty much.”

Xi leaned forward on the table. Her posture was extremely proper. “Ms.

Stratt has not told you the most important part yet.”

The Russian nodded. It was the first time I’d seen him move at all. Xi continued. “Do you know what Tau Ceti is?”

“Do I know?” I said. “I mean—I know it’s a star. It’s about twelve light- years away, I think.”

“Eleven point nine,” said Xi. “Very good. Most would not know that.” “I teach junior high school science,” I said. “These things come up.”

Xi and the Russian shot each other surprised looks. Then they both looked at Stratt.

Stratt stared them down. “There’s more to him than that.”

Xi regained her composure (not that she’d lost much of it anyway). “Ahem. In any event, Tau Ceti is very much inside the cluster of infected stars. In fact, it is near the center.”

“Okay,” I said. “I’m sensing there’s something special about it?”

“It is not infected,” Xi said. “Every star around it is. There are two very infected stars well within eight light-years of Tau Ceti, yet it remains unaffected.”

“Why?”

Stratt shuffled through her papers. “That’s what we want to find out. So we’re going to make a ship and send it there.”

I snorted. “You can’t just ‘make’ an interstellar ship. We don’t have the technology. We don’t have anything close to the technology.”

The Russian spoke for the first time. “Actually, my friend, we do.” Stratt gestured to the Russian. “Dr. Komorov is—”

“Please call me Dimitri,” he said.

“Dimitri heads up the Russian Federation’s research into Astrophage,” she said.

“It is pleasure to meet you,” he said. “I am happy to report that we can actually make interstellar voyage.”

“No, we can’t,” I said. “Unless you’ve got an alien spaceship you never told anyone about.”

“In a way, we do,” he said. “We have many alien spaceships. We call them Astrophage. You see? My group has studied the energy management of Astrophage. It is very interesting.”

I suddenly forgot everything else going on in the room. “Oh God, please tell me you understand where the heat goes. I can’t figure out what the heck it’s doing with the heat energy!”

“We have figured this out, yes,” said Dimitri. “With lasers. It was very illuminating experiment.”

“Was that a pun?” “It was!”

“Good one!”

We both laughed. Stratt glared at us.

Dimitri cleared his throat. “Er…yes. We pointed tight-focus one-kilowatt laser at a single Astrophage cell. As usual, it did not get hotter. But after twenty-five minutes, light starts to bounce off. Our little Astrophage is full. Good meal. It consumed 1.5 megajoules of light energy. Does not want more. But this is very much energy! Where does it put all this energy?”

I’m leaning way too far forward over the table, but I can’t help myself. “Where?!”

“We measure Astrophage cell before and after experiment, of course.” “Of course.”

“Astrophage cell is now seventeen nanograms heavier. You can see where this goes, yes?”

“No, it can’t be. It must have gained that weight from reactions with the air or something.”

“No, it was in a vacuum for the test, of course.”

“Oh my God.” I was giddy. “Seventeen nanograms…times nine times ten to the sixteenth…1.5 megajoules!”

I flopped back into my chair. “Holy…I mean just…wow!” “This was how I felt, yes.”

Mass conversion. As the great Albert Einstein once said: E = mc2. There’s an absurd amount of energy in mass. A modern nuclear plant can power an entire city for a year with the energy stored in just one kilogram of Uranium.

Yes. That’s it. The entire output of a nuclear reactor for a year comes from a single kilogram of mass.

Astrophage can, apparently, do this in either direction. It takes heat energy and somehow turns it into mass. Then when it wants the energy back, it turns that mass back into energy—in the form of Petrova-frequency light. And it uses that to propel itself along in space. So not only is it a perfect energy- storage medium, it’s a perfect spaceship engine.

Evolution can be insanely effective when you leave it alone for a few billion years.

I rub my head. “This is just crazy. In a good way, though. Is it internally producing antimatter, you think? Something like that?”

“We do not know. But it definitely increases in mass. And then, after using light as thrust, it loses mass appropriate to energy released.”

“That’s…! Dimitri, I want to hang out with you. Like—can we hang out? I’ll buy you a beer. Or vodka. Or anything. I bet there’s an officers’ club on this boat, right?”

“It would be my pleasure.”

“Glad you’re making friends,” said Stratt. “But you’ve got a lot of work to do before you start hitting the bars.”

“Me? What do I have to do?”

“You need to design and create an Astrophage-breeding facility.”

I blinked. Then I shot to my feet. “You’re going to make an Astrophage- powered ship!”

They all nodded.

“Holy cow! It’s the most efficient rocket fuel ever! How much would we need to—oh. Two million kilograms, right? That’s why you wanted to know how long it would take to make that much?”

“Yes,” said Xi. “For a one hundred thousand kilogram ship, we would need two million kilograms of Astrophage to get it to Tau Ceti. And, thanks to you, we now know how to activate the Astrophage and make it generate thrust at will.”

I sat back down, pulled out my phone, and launched the calculator app. “This would take, like…a lot of energy. Like, more energy than the world

has. It would be around ten to the twenty-third Joules. The largest nuclear reactor on Earth makes about eight gigawatts. It would take that reactor two million years to create that much energy.”

“We have ideas for finding the energy,” said Stratt. “Your job is to make the breeder. Start small and get a prototype going.”

“Okay, sure,” I said. “But I didn’t exactly love the ‘militaries of the world’ grand tour on the way here. Can I take a passenger jet home? Coach is fine.”

“You are home,” said Stratt. “The flight hangar is empty. Just tell me what you need—including staff—and I’ll make it happen.”

I looked at the others in the conference room. Xi, Voigt, and Dimitri all nodded. Yes, this was real. No, Stratt wasn’t kidding.

“Why?!” I demanded. “Why the heck can’t you just be normal, Stratt?! If you want fast military transport, well, okay, but why not just work at an air base or something sane people would do?!”

“Because we’ll be experimenting with a bunch of Astrophage once we breed it up. And if we accidentally activate even a couple of kilograms of that stuff, the resulting explosion will be bigger than the largest nuclear bomb ever made.”

“Tsar Bomba,” said Dimitri. “Made by my country. Fifty megatons.

Boom.”

Stratt continued. “So we’d rather be out in the middle of the ocean where we won’t eradicate any cities.”

“Oh,” I said.

“And as we get more and more Astrophage, we’ll go further and further out to sea. Anyway. Head down to the hangar deck. I have carpenters building accommodations and offices as we speak. Pick some you like and lay claim.”

“This is our life now,” said Dimitri. “Welcome