Hanna Svensson and her son Christian were close to bringing down Davor Mimica's criminal network which Christian infiltrated. Christian fled abroad. Now Hanna has to find a leak within the police for Christian to be able to return home.
Christian is back. In order to protect him, Hanna must find the police leak that was sold to a circle of corrupt police officers. She must take a decision. Should she let Christian infiltrate the circle to find out who the police leak is?
Dubravka Mimica gets word that her daughter Blanka has returned and begins looking for her. Blanka is pregnant with Christian's child, and Hanna is keeping her hidden. But how long can she keep this a secret from Christian?
Hanna and Björn know that Magnus is the Leak, but he has disappeared without a trace and seems impossible to find. Hanna wants Christian to quit now that they know who the Leak is.
The Mimicas are a huge threat, and Christian becomes obsessed with finding out if Davor has returned. Now Hanna and Björn have to handle not just them, but also The Circle and the new organisation they don't know anything about as yet.
A murder throws the investigation into chaos as The Circle reveals its true power and the strain on Christian may prove to be too much; if he is exposed, all is lost.