Without knowing the identity of an American serial killer who's on a plane flying from New York City to Stockholm, the A-Unit tries to find him.

While vacationing in the Netherlands, a Swedish family is killed by a car bomb and it's up to the A-Unit to solve the case.

Continuing their probe into the car bombing leads the A-Unit to a shady celebrity restaurateur and a Dutch drug-smuggling ring.

When an illegal African immigrant is shot and killed by police, Kerstin Holm is assigned the task of interviewing the police officer. He happens to be her ex-boyfriend Dag Lundmark, who then disappears without a trace during the investigation.

A Unit discovers a link between the shooting of an illegal African immigrant, bodies found in a marsh in Varmland and an apparent suicide. Kerstin Holm tries to track down missing police officer Dag Lundmark single-handedly. Suddenly she realises that he has come across a terrible secret and is just waiting for her to find him.

The A-Unit has its hands full when celebrated Jewish neuroscientist Leonard Sheinkman is found murdered, strung up from a tree in a Jewish cemetery; a group of women escape from an immigration board hostel, where they are being exploited as prostitutes, and flee the country; and a body is found half eaten in the wolverine enclosure of a Stockholm zoo.