Joona Linna finds herself in danger again and only Saga Bauer can save her.

Three years ago, Saga Bauer received a postcard with threatening text about a gun with nine white bullets, one of which was waiting for Joona Linna. The message was accompanied by the claim that only Saga could save him. She did show the postcard to Joon at the time, but time passed and the threat fell into oblivion as an insignificant provocation. Until now.
A bag with an almost decomposed body was found in the old cemetery in Kapellskär. A white shell casing was left at the crime scene. A beastly criminal gives the police the ability to stop a series of murders by solving complex puzzles.

Joona Linna and Saga Bauer work together to solve the complicated case and save the targeted victims — before it's too late. However, they are increasingly desperate in their pursuit. What if this serial killer is unstoppable? And what if they themselves are already caught in his net?