Seventeen-year-old Victoria Abermath has always kept her head down and buried her mental health struggles in books. The last thing she needs is Indigo Emerson. He's a violent, infuriatingly arrogant boy who seems connected to her in a way she can't explain. Both of their parents are locked away at Haglin War Prison, wrongly accused of being American-born terrorists, but getting information out of Indigo is like pulling teeth.
When Victoria and Indigo are tricked into drinking a body-controlling serum, they wake up inside a criminal enterprise posing as the CIA. Run by Dr. Lancaster Schilling, the organization takes them and eight other teenagers deep into a compound in the Rocky Mountains. There, the ten kids must fight through life-threatening challenges with only one winner. If they succeed, they keep their autonomy; if they lose, they become Schilling's automated assassins until the day they die.
Victoria refuses to become a weapon. But surviving means trusting Indigo, the one person who knows more than he's saying about their parents, the prison, and why they were brought together. As the trials grow deadlier, their hostility ignites into something far more dangerous: affection. But romance will only distract them. They must focus on piecing together the clues left by their parents. If they fail, they'll be activated, and their parents will spend the rest of their lives in a place worse than death.