Tree Gelbman awakes in a stranger's dorm room on her birthday. However, her mate from the previous night is the least of her worries. The day runs its course as expected until Tree is stalked and murdered by an unknown assailant. Life goes black for Tree, and then she suddenly reawakens in the dorm room again.
It turns out she is stuck in an endless loop of the same day with the same murderous fate. Tree eventually finds out she must discover her killer's identity and motive to escape the situation. As she relives her birthday over and over, it becomes less clear whether Tree will eventually wake up the following day.