In Sweden, there are 163,271 people with the surname Karlsson. All with different dreams and lives but with one thing in common, their last name. In the comedy series Alla vi Karlssons, we get to follow some of them and see what they struggle with.

In a playground in the centre of the urban idyll, the police find a buried wooden box containing a famous and well-respected prosecutor. Martin Beck and his police team initially suspect a highly criminal MC-leader of the attack, but one pretty soon has to re-evaluate the case once the MC-leader is found murdered in a similar wooden box. Soon, more wooden boxes are found and the police realize that they are part of a cat and mouse game with a crazy serial killer. The investigation soon shows that there is a vague connection between the victims in the shape of a 9 year old event, but what Martin Beck does not suspect is that his own life too is at stake, as the murderer has chosen him as the next victim.

A paparazzi photographer gets brutally murdered in Stockholm. His apartment is searched and the computer together with photo equipment is missing.

Two young girls are killed on railway by a passing train. It does not seem to fit the profile of a normal suicide. So if this is a double homicide who would do this and why? Martin Beck and his team start following the step backwards in order to figure out what has happened. With good and intensive police work they find man side trails from the main path.

A teenage girl is found by her parents brutally raped and murdered in the woods. It's now up to Beck and his team to catch the criminal.

After a woman buys a Japanese shunga painting from an auction and later is found murdered in a hotel in Stockholm, the police gets dragged into a murder investigation where they meet the dark side of the art world.

The murder of a prominent attorney is connected to one of his recent cases, in which a company was being sued for serious environmental damage. Martin Beck and Lena Klingström find evidence which brings new light to the investigation - but who's pulling the strings?

Swedish politician John Veden vanishes without a trace. There's no hint he's dead yet but Beck's team gets the case due to Police Chief Oberg's friendship with the man whom she dined with him the evening before he vanished. When they find out Veden was a gambler with heavy debts battling his addiction the case leads Martin Beck, Gunvald Larsson and freshly returned Lena Klingström into Sweden's illegal gambling scene. And Veden was planning to expose his own addiction and his party's huge financial profits from gambling in a confessional book - which his political allies got wind of via illegal data theft. With several people having an interest that Veden stays missing the team tries to find the politician and the true perpetrator while Beck is grappling privately with his ambivalent feelings about working with ex Lena again....

A small girl is found dead in a deserted underground cellar. She has been dead for some time but there is fresh food for her. Who is she?

An abused woman is feverishly sought by police in the murder of her ex-husband but is being hidden by abused woman-advocates. At the same time, Gunvald Larsson discovers a police report that his long-estranged sister has been abused. He confronts her with his knowledge but she denies it.

High school student Mikaela is attracted by her Swedish teacher Göran and writes an erotic novel for his class.