Ten students at a high school end up being trapped in the school overnight after being detained for bad behavior. What seemed to be just a boring night turns into a true nightmare when the group realizes that there is a killer among them, who is willing to kill one by one. They are isolated from the outside world and trapped in a dark and creepy building, not knowing who they can trust. The assassin seems to know all of the group's secrets and weaknesses, and begins to use them to further terrorize them. With time running against them, the group must work together to uncover the killer's identity before it's too late. As they fight for survival, they discover that the secrets they hide are much darker than they imagined and that the real threat may be closer than they ever imagined.
