1908. Jan Edigey-Korycki comes back to Cracow after spending ten years away. He wants to examine the circumstances of his mother's death and soon discovers she may have been murdered by a serial killer.

A mutilated body of a young woman is found in a village near Cracow. People are quick to blame a local Jewish family, but Jan is not convinced that they are guilty.

A burned body of a young woman is found by firefighters, but it turns out that she did not die in the fire but was murdered. Soon Jan discovers that the woman had an illegitimate child.

An army major and his wife are found dead in their villa. Their daughter is injured, but she claims she doesn't remember much. With the army conducting their own investigation, Jan is pressured to solve the case as quickly as possible.

Two young boys find a body in a forest near train rails. Victim's skull was crushed, which makes identifying the body difficult, but Jan finds evidence connecting the case with a nearby coal mine.

A dying man is brought to a hospital with a cracked skull and before dying he says the name Adolf. The police investigates a street market where the man was found. In the meantime, Jan is also investigating his fatal duel with Lucjan.

In Lwów, a boxing champion Wiktor Pronobis is fighting his last fight before retirement. Meanwhile in Krakow his infant son is kidnapped. Since the kidnapper seems to have known the house well, the police suspect a servant may be guilty.

Body of a young woman is found in a place frequented by people who are in love. The police investigate whether her death was a suicide or a murder, which is made more difficult by the fact that they don't know the victim's identity.

A body of what is assumed to be a prostitute is found in a brothel. Soon it turns out that the deceased was in fact a male judge, who enjoyed crossdressing and had masochistic tendencies.

The antique dealer who might have been the key to solving the mystery of the fatal duel between Jan and Lucjan is found dead. All evidence points to a woman as the killer. Meanwhile, Jan and Konstancja are getting ready for their wedding.