Three Swedish financiers are murdered over three consecutive nights. Evidence suggests that the killings will continue and the world of finance is panicked. The police quickly set up a special unit under the leadership of Detective Jenny Hultin. She hand picks six police officers from across the country and they form the so-called A-group.
An American serial killer is on board a plane from New York to Stockholm. Without a proper identification and with great urgency A-group try to locate this passenger before Sweden inadvertently imports it's first American serial killer. The serial killer enters Sweden, and very soon he begins his killing spree.
When a Swedish family is on a road trip in Holland are killed by a car bomb, the case is immediately handed over to the A-group to investigate.
A police officer shoots and kills an African immigrant who is going to be deported from Sweden. Kerstin Holm is assigned the task of interviewing the police officer, who turns out to be her ex-boyfriend, Dag Lundmark. During a break in the interview, Lundmark disappears without a trace. Meanwhile, a burglar breaks into an apartment where he finds a body with a suicide note next to it.
The A Unit has its hands full with Ukraniam prostitutes, the Mafia, and a murdered 92 year old neuroscientist, while Hultin is under pressure to downsize the team.
A series of brutal murders of Polish women hiding out in Sweden is the new A Unit's first assignment. The victims turn out to be key witnesses in a big case against the Polish mafia. Three of them are found murdered within a couple of days, and two are missing. The hope is that the missing women are still alive. Chief Inspector Kerstin Holm gets the case, and the hunt for a ruthless murderer and his shady victims begins.
Kerstin is caught up in a murderous bank robbery by two Russians, but a third man's participation proves puzzling, and the A Unit investigation suggests a Cold War connection.
A Swedish biker gang's link to trafficking two teenage girls to Belgium means A Unit is already on the case when a another girl goes missing. Paul Hjelm investigates a claim against a vice squad officer.
Swedish crime drama. Ida is frustrated at how tantalisingly close the team came to saving the abducted girl.
Stockholm is rocked by an explosion on an underground train. When A Unit begin investigating, they uncover a fascist gang with ties to far-right groups all across Europe and its leader becomes their prime suspect. Kerstin is struggling to come to terms with the death of Bengt and her working relationship with Paul suffers as a result.
In their search for the bombers of an underground train, 'A' Unit have uncovered a fascist gang with links to terrorists across Europe. But as their net tightens around the suspects, another survivor emerges from a hiding place in the tunnel with information that will take the investigation in surprising new directions
A woman is found collapsed in the street, having escaped from an unknown basement. She has no idea why she was kidnapped and, with nothing else to go on, 'A' Unit follow a lead found in the basement to a drugs ring run by two brothers.
Investigating a series of murders and kidnaps, 'A' Unit begin to suspect they are linked to a shared high school experience - but this still isn't getting them any closer to catching the killer. Paul is investigating the sudden and mysterious death of his new-found friend from the security service.
