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!

Rasmus has discovered Freddie's abandoned helicopter in a disused concrete factory and is told to wait for back-up.

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.

A captive Jeanette's whereabouts are located by Freddie using a tracking device and, with all resources being utilised to investigate the kidnapping, Saga is brought back from suspension to help Henrik follow a tip on who is behind the abduction.

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.

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.

The crime spree is resolved. However, many loose threads remain.

Henrik and Saga suspect that Taariq and the missing expert on left-wing radicals are hiding something, and collaborate to reveal them. They disagree on how to handle the homeless girls who still refuse to give up their identity.

Taariq recognizes a car related to the case. He wants to push the owner for money, but is himself accused of robbery. Saga fears that will be more murders and Henrik's efforts for the homeless girls end up in disappointment.

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.

Saga and her new partner Henrik grow closer together while new discoveries shed light on how the murder cases are linked together.

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 chemical plant is attacked which threatens to contaminate a water source. Saga realises living with a partner is harder than she thought. Martin looks into Saga's past.

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.

Knowing the killer has carefully planned his crimes, Saga and Martin wonder whether they can catch him off guard by doing something he doesn't expect.

The hunt is on for the leader of the eco-terrorists, with Saga and Martin hoping to stop any further attacks from happening.

Saga and Martin have a sketch of the suspect, but can they get to them in time to avert 'The Graduation'. Their friendship is placed under strain by Martins inquiry into Saga's past.

Saga and her new partner Henrik follow leads in finding their kidnapped boss Hans. In the meantime personal developments in Saga's life influence her work as a police officer.

The murderer has groomed a number of schizophrenics to commit carefully synchronized violent crimes on the same day in Malmo and Copenhagen.

A rogue policeman is killed by someone in uniform. The detectives believe that the killer for whom they are searching was the killer. They also now suspect that the killer may indeed be one of them - that he is actually is a cop.

Because the detectives suspect that a policeman is involved, a profile of the killer is developed and several police fit the profile and a search among them begins. The hunt continues and a particular suspect is found.

Things are brought closer to home when the criminal's mask is removed.

As the investigation moves forward a new group of four, animal head wearing, eco-terrorists post a video online. Saga is having some relationship "issues".

It becomes apparent that the case isn't over and Saga and Martin race to prevent another terrorist attack. Saga faces a decision that may destroy her friendship with Martin.