Five years ago, Alice Ejbye's 18-year-old son Markus was murdered by a serial killer who was never found; Alice is now seriously ill and asks criminal profiler, Louise Bergstein, the daughter of her best friend, to help solve the case.
A young man has been found in the woods, tortured and stabbed to death. Louise Bergstein and Karina Horup try to find evidence for whether the murder can be attributed to a serial killer who, after a five-year hiatus, may now be active again.
Louise and Karina know that William Fjeldby is the serial killer's victim, but his father clings to hope that he's alive. Johannes suspects his father's hiding something.
Alice offers a reward for information about who killed her son, but Karina and Louise struggle to find a useful tip; Peter takes his frustration out on his next victim.
Alice's death takes the investigation in a new direction; Karina gives Louise an ultimatum; Peter receives an offer from Leif; Johannes rebels against his father.
Karina and Louise return to the first victims to learn where they may have met their killer; Peter realises the police are getting closer and happens to see Louise again.
Unaware of who he really was, Louise has spent a night with Peter; an earlier clue resurfaces, moving the case forward; Peter gives Johannes a hard message to accept.
The police take Johannes to the police station; Peter meets with his ex-wife, who has returned from Singapore; Karina, Soren, and Torben desperately try to find Peter.
