A new murder is commited involving a gruesome display of a family sitting at the table. Detective Saga Norén is tasked with the investigation together with a new Danish detective after the incarceration of Martin Rohde.

With the detectives now working on two so-called 'clown murders', a prime suspect is the traumatised son of the first victim, who is on the run. The usually phlegmatic Saga is distracted from the investigation by the unwelcome appearance of her mother, who insists on showing her a medical file, hoping to find a resolution to their estrangement.

Saga and Henrik interview the estranged sister of the latest victim, who mentions that he had been cautioned after complaints from some of his pupils. Whilst nursing the hospitalised Hans, Lillian discovers a wound inside his cheek and Saga immediately orders the re-examination of previous victims. Claus attends the gallery opening of works from Freddie Holst's private collection and is alarmed when Anneka arrives and demands admittance.

A sceptical Henrik and Saga are initially unimpressed when a young art curator suggests a connection between the murders of Helle Anker and Lars-Ove Abrahamsson and the brutal attack on Hans, but his theory leads them to interview Freddie Holst, a successful businessman with a substantial art collection. The detectives are called to yet another victim whose mutilation seems to be the work of their serial killer.

Burglars make the gruesome discovery of two new victims, which Henrik recognises reflect the title of another of Freddie Holst's artworks called Cancel Christmas. The victims were foster carers and, whilst the team await a list of their charges, Saga and Henrik receive a breakthrough lead from John's new girlfriend Tina, who has been staking out the Holst house.

As the Internal Affairs investigation continues over the death of Saga's mother, the pressure on her becomes intense. Saga, Henrik and John receive new leads when it becomes clear a potential suspect in the mysterious serial killings is actually a victim.

Saga and Henrik keep searching for a link between the murder victims. Lillian is reprimanded by her superiors. Dan finds out where his ex-wife and son are and causes trouble. The relationship between Saga and Henrik is tested to the limit and may have hit its breaking point.

Henrik believes he found the connection between all victims and an unexpected finding ends up on the investigation board. At the same time, the crack between him and Saga is greater than ever.

The inquiry into Tommy continues and Solveig still refuses to cooperate. She talks neither with Saga nor Jonas. The question is how long they can keep her in holding if they do not obtain any evidence. Lillian is still under pressure from the management to find the culprit, and now it seems that there is a leak in the department. In the meantime Saga makes a breakthrough in the search for Henrik's family.

Henrik and Astrid are trying to get used to being father and daughter again. Meanwhile Saga gets a breakthrough and the murderer is revealed and arrested under dramatic circumstances. The murderer even confesses to the six killings/revenges. But Saga discovers something which doesn't fit. She goes back to the prison in Sweden and talks to the girl who almost killed her, and here she gets a terrible suspicion: there is another killer - and there is still one person left to be a victim!