The body of high school student Joanna Walewska is discovered by three of her peers. Police initially believe that she may have committed suicide, but they soon find out there is more to the incident.

Police begin to interview students, under the supervision of their principal. They are joined by a psychologist, as they learn more about who Joanna really was.

Marta realises that the deed of sale for the property is partly fraudulent after examining it more closely. The police discover that some of the DNA samples were tampered with.

Lieutenant Kedzierski is alarmed by the surgical precision conducted in another recent murder. He realises he needs Pawel's help, and asks him to formally aid the police.