Janet has come up with the excuse of a party to relieve the tensions between their two trigonometry study groups. During the party the kids play a murder game, pretending that their trigonometry teacher is the victim. The students become edgy because of the parallels between their characters and themselves. All calm is shattered when word comes that their trigonometry teacher actually has been murdered! Everyone has a theory about who killed the teacher. Amidst the finger pointing and scrambling for alibis, "evidence" shows up in bookbags, and friends become enemies as suspicion rears its head. When the "real" murder turns out to be a fake, Janet's motives are revealed and the teens make some important realizations about each other and themselves.