Karol, an ordinary young man, runs into a much older man, whom he believes to be a Red Spider, the terrifying serial killer, prowling the streets of Cracow in 1960s. Karol becomes obsessed with the man and spies on him.

A cop is found dead in a hotel, brutally murdered, a spider cut into his stomach. The police believes his death might be connected to the fact that he was a dirty cop - the internal affairs commission already was after him - but then several other people are murdered in the very same way, and there seems to be no connection between the cases. The police seeks for a blonde woman among the prostitutes.