Après s'être séparée de son fiancé infidèle, une jeune professeur de collège emménage chez sa soeur et croise la route d'un locataire séduisant.

A young woman develops a dangerous, obsessive friendship with her new roommate and plots to murder all those who she feels have done her new friend wrong.

A woman advertising for a new roommate finds that something very strange is going on with the tenant who decides to move in.