Detective Sarah Lund is about to move to Sweden with her boyfriend and son, but her plans are derailed when she receives a disturbing dispatch. When it's discovered that a prominent politician might be connected, the case's stakes get higher.

Theis and Pernille's worst nightmare comes true when it's confirmed that they're 19-year-old daughter Nanna has been found. The car she is found in is linked to the office of mayoral candidate Troels. Sarah postpones her move for a week.

Sarah and Jan track down the driver of the car but Jan's impatience deters the investigation. Troels and his political advisor, Rie, realize that confidential information is being leaked from their office. Is it the police or someone internal?

Sarah and Jan find suspicious evidence in the high school basement and zero in on Nanna's ex-boyfriend Oliver and his friend Jeppe. Troels and Rie try to eliminate the leak as the crime begins to increasingly affect his campaign.

Sarah realizes that Nanna's friend Lisa may be hiding something about the night Nanna disappeared. New information turns Sarah and Jan's attention to another lead. Rie tries to steer Troel's campaign out of trouble.

Troels lands in more trouble when someone who is part of his campaign becomes a suspect, and the police believe he tried to hide this information. As Pernille and Theis say goodbye to their daughter, Theis inserts himself in the case.

Just when Jan thinks he's in charge of the case, Sarah returns after learning worrying information about Theis. All evidence now seems to point to Troels's campaign connection, forcing Troels to choose between his advisors and his own morals.

After Sarah and Jan find more damning evidence, Troels is presented with an ultimatum and his candidacy hangs in the balance. Just when Theis and Pernille believe that the case is coming to a close, something inexplicable happens.

Theis and Vagn have taken the law into their own hands, stalling the investigation. Sarah and Jan have 24 hours to find conclusive information or they will be taken off the case. Troels's campaign undergoes a radical change.

Sarah and Jan pursue a vital new lead but are taken by surprise when someone unexpected intervenes. In her personal life, drastic personal changes affect Sarah. Meanwhile, Troels attempts to establish a new alliance.

Sarah discovers an apartment that provides crucial evidence in the case. She and Jan now know who they're looking for but are puzzled by their superior officers' reactions. Troels is under greater pressure than ever in both his work and private life.

Sarah and Jan interrogate Troels, who divulges private information that leads to a potential breakthrough in the case. New evidence further puts the spotlight on him. Theis and Pernille's marriage has reached a turning point.

Now under scrutiny by both the police and the media, Troels's political career is crumbling. Meanwhile, strange things happen at the town hall with serious consequences. More problems arise in Sarah's private life.

The police have a new lead who holds the key to Nanna's death, but getting that information from him is another story. Still in the limelight, Troels's political support is waning, and his opponent takes advantage of the situation.

Sarah puts herself in a life-threatening situation, and neither Jan nor anyone else knows where she is. Meanwhile, the pieces are falling into place regarding the perpetrator. Bremer tries to ruin Troels's political career once and for all.

Sarah and Jan's boss declares Nanna's case solved, but Sarah is not convinced they have the right person. As she continues the investigation alone, her personal life falls apart even more. Troels has something to reveal to Bremer.

Sarah and Jan discover a critical link to Nanna's murder and embark on a race-against-time hunt for the killer. Nanna's last message leaves Pernille and Theis with more questions than answers. Troels is prepared to put everything on the line.

When Sarah and Jan go to a warehouse to look for evidence, things take a dire turn. Troels is contacted by a journalist who seems to know more than they should. Theis and Pernille find surprising evidence in their new house.

As the police hunt for a recently missing person takes an unexpected turn, Sarah is plagued by problems in every aspect of her life. Troels and Bremer have a game-changing debate on live TV. There's something off with Theis and Pernille's new house.

Sarah has been taken off the case, but she's sure of the killer's identity and continues investigating on her own. How will she succeed without incriminating evidence? Pernille and Theis's birthday party for Anton turns into an eventful night.