Teenagers Meg and her friend Minnie find themselves invited to a party on a private island. The invitation comes from the popular girl at school, so they accept. The party includes TJ, Meg's crush, and Ben, but does not include parents. While waiting for the hostess, Ben and Minnie start hitting it off right away, leaving Meg to wonder about TJ and whether or not to make a move. There are ten people at the party.
But then one of the party guests turns up dead. Suddenly, it becomes clear that someone amongst the group has purposely used the party as a way to exact some sort of vengeance. None of the guests know who the killer is, so they also don't know who the potential targets might be. Meg decides to search the island for the killer, or at least to determine whether the killer is part of the party by process of elimination.
Then people start to die, and they're discovered by the two main girls, usually with wounds that correspond to something they have said or done, either at school or at the party. Eventually, they formulate a theory that Nathan is the killer, but then Nathan turns up dead. In the end, it is discovered that "Ben" is actually Tom in disguise, having killed the real Ben and assumed his identity to exact vengeance for the death of his sister.
