A man working at a garbage incinerator watches the body of a dead man burned to ashes in the oven. Police detective Martin Beck handles the case. All he knows is that a brutal murder has happened. But he does not know when or where. He has no body, motive or a crime scene, not a single trace. All he has is some teeth and a mysterious Internet adress.

Beck and his men investigate the murder of a Russian woman. At the same time, SÄPO (The Swedish Security Agency) sees a chance of getting a Russian in the embassy deported.

When the police uncover a narcotics smuggling operation, the driver is shot dead. The man turns out to be Superintendent Martin Beck's son. Beck breaks down and steps away from the investigation but later returns at his colleagues request.

Beck and his team are trying to find a serial killer whose victims are spread all over Sweden. An obvious connection is that all the victims are women, and they were all in the same class, and Beck thinks that a scandal back in the past has something to do with the murders. But no one wants to talk about the past and it becomes a struggle to find the perpetrator before the final murder - only one woman is still alive.

Inspector Beck and his team get involved in a large-scale smuggling of cesium 133. A gang from the east uses refugees who with a promise to stay in Sweden and with danger to their own life take in the dangerous explosive chemical substance.

A bomb threat is called in to a police station in Stockholm. The police bomb squad blows the briefcase to pieces and it looks like false alarm, until a baby is found inside. Soon, e-mails are sent out to every newspaper about the nasty situation that the police had tried to keep secret. Will the police ever overcome the "Monster"?

A homosexual police officer's double life is paid by Beck's archenemy, Gavling, a man who runs Stockholm's underworld. In return, the officer has been providing Gavling with secret information from the police archives.