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.
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.