This isn't the game they signed up for. Eighteen-year-old Carmody Foster and her classmates just became Senior Assassins armed with water guns. As part of a tradition, they've joined the game, the last hurrah before graduation. The premise is simple: Within the established rules set up by an anonymous council known as The Syndicate, eliminate your assigned targets. But The Syndicate isn't playing by the rules, isn't playing a game-they're playing for real. When someone gets eliminated, they face real-world repercussions because The Syndicate publicizes one of their secrets. Failure to eliminate their targets by graduation will also result in exposed secrets. When the players attempt to quit, The Syndicate sends a message: keep playing or risk physical injury from them. Terrified of having her darkest truths revealed and her classmates never viewing her the same again, Carmody fights to stay alive in the game while she and her friends try to unmask and stop The Syndicate before they hurt anyone else.