Two traffic officers on a quiet morning shift try to stop a car for speeding. When the car finally pulls over, the driver gets out and shoots at them, killing one of the officers in cold blood. A national alert is issued and an extensive search for the ruthless killer begins, with the Beck group at the lead. Neither the officer's shocked and wounded colleague nor any of the witnesses have seen anything helpful to the police. Finally, they find the car registration number using a surveillance camera. But, when they enter the car owner's apartment, they find him shot to death. The first day of summer is a long one for the Beck group, as the killer has more victims on his list.

Three brutal murders are committed in a house in a quiet suburb. The victims are a former police officer, his wife and their 10 year old son. The Beck group takes on the case and find that there is a hidden security room in the victims' house, containing stolen weapons. They find fingerprints from a criminal who was involved in a robbery 4 years ago. After the robbery, he shot his accomplices and disappeared without a trace, along with their haul of 6.3 million.

An unidentified body is found in the remains left after a fire in a trailer at a run-down caravan park. The owner of the trailer, a young drug-addicted woman, is missing, but is she really the victim? And what role has the so-called neighborhoods watch from the nearby community played? The case is difficult to solve, with everyone involved guarding their secrets, regardless of social class. Furthermore, police supervisor Klas Fredén decides to go over Martin Beck's head and recruit charismatic, Norwegian homicide investigator, Steinar Hovland. 

An investigative journalist is found beaten to death in his home, where the fingerprints of a notorious criminal debt collector are also found. The murdered journalist has been threatened by right wing extremists, but it is the victim's work with a book about "society's dark side" that captures the Beck group's interest. When the case takes an unexpected and terrible turn, there is suddenly much more at stake than finding the journalist's killer. Martin Beck and his colleagues have never had to protect the balance of their professional and private lives with the same tenacity as they do now.

An elderly woman dies in a hospital in Stockholm and it turns out that she suffered from an incurable disease. Her son though refuse to believe that it was the disease that was the primary cause of her death.

The bodies of two buried men are found and despite persistent attempts, they cannot be identified. When another man is murdered, police discover new evidence that soon leads them to an Islamist terrorist cell.

A well-known crime boss is murdered by a sniper in front of his family.

A young woman is found strangled in a hotel room. The investigation leads Beck and Gunvald to Stureplan, Stockholm's nightlife and its downsides.