Gigi’s hair was a little too excited about being on a boat—specifically, a speedboat, and even more specifically, an Outerlimits SL-52.

In a game like this one, details mattered. Gigi clocked it all. The fire- engine-red detailing on the boat. Its impressive, fifty-one-foot length. The island toward which they were hurtling.

The Hawthorne driving the boat.

Gigi’s always-wild, two-inches-below-chin-length waves danced madly in the wind, flying in every direction at once, like they were trying to make a break for it.

“You didn’t bring a hair tie,” Savannah said beside her, not a question but a statement of fact. Based on experience, Gigi expected her twin to slip an extra hair tie off her own long, pale braid, but Savannah made no move to do so.

Things between them had changed since Savannah had left for college. Since before that.

Gigi hated lying to her twin, and everything short of blurting out the whole sordid truth always felt like a lie. Dad isn’t in the Maldives—he’s dead! He died trying to kill Avery Grambs! There was a cover-up! He also blew up a plane! Two men were killed.

A chunk of hair thwapped Gigi in the face.

“Here.” A quiet, baritone voice broke through the wind. Gigi turned to look at the remaining passenger on the boat—the remaining player. He held

out a hair tie identical to the one that held back his own shoulder-length dreadlocks.

“Thanks,” Gigi said. After she’d put his gift to use, she beamed at him. “I’m Gigi,” she declared. “And you’re my new best friend.”

That got her a slight smile, as her new friend (and also: opponent) fixed his gaze on the island in the distance. He had deep ebony skin and wore thick-rimmed glasses, and there was stubble along his rather remarkable jawline.

Okay, his totally remarkable jawline.

Gigi waited for him to say something else, but he didn’t. The strong and silent type? Luckily, she excelled at filling silences. “I love islands. Private islands. Deserted islands. Peculiar island towns full of quirky people.”

Next to her, Savannah sat with perfect posture, not a hair out of place, as poised on a boat as she would have been on a throne. She didn’t say a word. “Take any book or movie and set it on an island,” Gigi continued, stubbornly cheerful, “and it gets about a thousand times better, no idea

why.”

“Closed system,” that quiet voice said.

Gigi looked again to her new friend/opponent. “Closed system?”

“In quantum physics, it’s a system that doesn’t exchange energy or matter with any other system. There are equivalent concepts in thermodynamics and classic mechanics. Chemistry and engineering, too.” He gave a little shrug. “Under those definitions, an island wouldn’t qualify, but the same concept applies. Nothing in, nothing out.”

“A closed system,” Gigi repeated. She amended her previous assessment: strong, not always silent, and nerdy! “Are you a physicist?” she asked.

Figuring out the competition would make it easier to beat him. And also: She wanted to know.

“Recovering.”

“A recovering physicist?” Gigi grinned.

“Currently I’m a third-year doctoral student in cultural anthropology.”

The boat began to slow, closing in on the island—and a dock. “Hypothetically speaking,” Gigi said to the recovering physicist, “how old are you and what is your name?”

That got her another very slight grin. “Twenty-one. And Brady Daniels.”

“He’s not your friend.” Savannah didn’t bother looking at Gigi. “He’s your competition. And if he’s a third-year graduate student at twenty-one, he finished his undergraduate degree at seventeen or eighteen at the latest.”

A prodigy. Gigi’s gaze cheated back toward Brady as the boat slid into the dock.

The boat’s driver, Xander Hawthorne, pumped a hand into the air. “Nothing but net!”

“It would be a mistake to trust anyone in this game,” Savannah told Gigi, climbing effortlessly out of the boat before Xander could even tie it to the dock. “Your new best friend here will take you out the first chance he gets.”

To anyone else, Savannah’s expression probably would have looked icy, standoffish, equal parts cool and calm, but Gigi recognized Savannah’s game face. That face was as good as an announcement: Savannah had come here to play, and Gigi knew better than most that the only way her taller, blonder, perfectly self-possessed, probably smarter, definitely more driven twin ever played…

Was to win.