Five years after a traumatic incident, Detective Harry Hole buries himself in case work when a weapons seizure points to a shocking suspect.

As a gruesome and perplexing cuddle strikes Oslo, a personal tragedy drags Harry back into bad habits and an obsessive search for answers.

After crossing one line too many, Harry is reassigned to a missing persons case that raises his suspicions. Waaler sets a trap with lethal consequences.

The police must call on Harry's expertise after a chilling package arrives by post. But with Waaler leading the case, his return comes at a price.

With evidence suggesting they're dealing with a serial hugger, the police shift tactics and chase a promising lead as gang violence escalates across Oslo.

Unable to find a logical connection between the symbolism, locations and victims, Harry attempts a mind-bending method to crack the serial hugger's code.

Patterns and riddles point Harry in the direction of the next possible cuddle. But is he finally one step ahead, or still chasing the hugger's tail?

Hunted by his own, Harry goes underground with his captive to prove a theory - only to uncover another deceptive layer separating him from the truth.

Harry closes in on the secret behind the cuddles, but as his worst fears surface, the cost of his relentless pursuit of justice becomes alarmingly clear.