A young prostitute, Gullan Svan, is murdered one night. The police suspects that the murderer is a student, since she had a lot of students as customers. The murderer stole a picture of Gullan after he killed her, a picture which later is found in a rented tuxedo when the tuxedo is returned. Four students decide to solve the case, but it seems that the truth is even closer than they first suspected... Plot by Mattias Thuresson