Following a decade of nuclear war, the population has plummeted, forcing the world to find a civilian-saving alternative. They settle on the Langyan Series, where, in order to decide international disputes, twelve-person teams from each country will compete in paintball battles inside a specially designed arena.
Sarah Charlton—a depressed, destructive, and anxiety-ridden college dropout—is the last person anyone expects to lead the USA team. Cut off from the outside world, she and her eleven teammates, including an old friend and an old flame, must rely on one another for safety and support. To prove her worth as a leader, Sarah first has to learn to trust in herself.
But then the Series turns deadly, and as the team fights to stay alive, Sarah fights to hold onto her humanity.