Three best friends enter the woods one day to play a game. The rules are simple; they are to survive for twenty-four hours, without the help of compasses, mobile phones, or timekeeping devices, all while avoiding the creature that is hunting them. If they win, the reward will be well worth it. But in order for Jenna, Lucian, and Harriet to keep themselves alive, they've got to stay together-- and the Apex excels at separating its prey and picking them off one by one, particularly if the Herd can't really trust each other.