A serial killer that decapitates people is on the loose in the Stockholm subway. Martin Beck and his colleagues try to catch the killer, while the panic in the city increases.
A homosexual police officer's double life is paid by Becks archenemy, Gavling. A man who runs Stockholm's underworld. In return have the homosexual police, been serving Gavling with secret information from the archive of the police authorities. Written
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.
In this film 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.