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 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.