"A deeply immersive story that balances fantastic, original world building with spine-tingling adventure." —Sabaa Tahir, #1 New York Times–bestselling author

It's been a century of peace since Earth became a colony of an alien race with far reaches into the galaxy. Some die-hard extremists still oppose alien rule on Earth, but Donovan Reyes isn't one of them. His dad holds the prestigious position of Prime Liaison in the collaborationist government, and Donovan's high social standing along with his exocel (a remarkable alien technology fused to his body) guarantee him a bright future in the security forces. That is, until a routine patrol goes awry and Donovan's abducted by the human revolutionary group Sapience.

When Sapience realizes who Donovan's father is, they think they've found the ultimate bargaining chip. But the Prime Liaison doesn't negotiate with terrorists, not even for his own son. Left in the hands of terrorists who have more uses for him dead than alive, the fate of Earth rests on Donovan's survival. Because if Sapience kills him, it could spark another intergalactic war. And Earth didn't win the last one . . .

"Exo is my favorite type of sci-fi adventure—a novel that makes you question everything you think about our world . . . and what it means to be human." —Kass Morgan, New York Times–bestselling author

"This action-packed novel asks readers to consider alien technology, what it means to be human or nonhuman, and the gray areas in war, where neither side is completely good or evil . . . Ethical questions add complex layers to this exciting sci-fi offering." — School Library Journal