In Helsinki, Finland, the mutilated body of a ritual murder victim is found at Suomenlinna Sea Fortress, and crime investigator Jan and his partner Heidi have a new case on their hands. Meanwhile, young journalist Saana gets fired from her job as click-bait celebrity news editor, and decides to spend the summer with her aunt in the small town of Hartola. It sounds like a perfect opportunity to take it easy and recover from mental and emotional burnout. But when Saana begins to dig into the case of a teenage girl who died 30 years earlier, the peace of the small town is shaken. Soon, more bodies start to pile up, with the same gruesome branding and skinning signs, and Jan and Heidi realize they are on the tracks of a serial murderer, probably killing for revenge. The next victim shows up in Hartola. Saana and Jan continue to work on their own cases until their paths cross - for more than one reason.