As the financial crisis grips Denmark, Sarah Lund is preparing to celebrate 25 years in the police force and facing big changes in her life. Amid the turbulent economic and political climate, a disturbing discovery is made in the harbor.

When the 9-year-old daughter of the Zeuthen family, who own shipping giant Zeeland, is kidnapped, Sarah leads the hunt. The kidnapping becomes a hot-button issue in the election campaign for Prime Minister Kristian Kamper.

Following a shocking death, it becomes clear what Emilie’s kidnapper’s motives really are. The Zeuthen family demand more action and all available resources from the police. Sarah tries to improve her working relationship with ex-lover Matthias.

Sarah and Matthias must choose between following the kidnapper’s instructions or devising their own plan, which could put Emilie’s life at further risk. New evidence points to a link between Emilie’s kidnapping and an old murder case.

The kidnapper continues to demand his debt be paid, but Sarah must figure out what the debt is and how it needs to be repaid. Emilie’s father, Robert Zeuthen, accepts a proposal by the kidnapper. The prime minister makes a dramatic decision.

Sarah and Matthias go to Jutland to follow the kidnapper’s trail but when they make a gruesome discovery, they find themselves in grave danger. Kamper’s campaign gets a break when it’s revealed that his opposition has been keeping a secret.

Tensions rise between Sarah and Matthias as they try to escape their dangerous situation. A boy’s notebook becomes a key piece of evidence when it reveals information that could connect the dots between several parties.

New information puts the prime minister and his relatives under scrutiny by the police. In an effort to learn the truth from Kamper, Matthias goes too far and is removed from the case. A new witness claims to know something about Emilie’s kidnapping.

The kidnapper now has a face—will he lead the police and the Zeuthen family to the truth? The prime minister investigates his own political circles to find out what happened with the old murder case. Robert and Maja get a glimpse of the kidnapper.

The kidnapper agrees to lead the police to the truth, throwing Sarah and Matthias in a tight race against time. Under pressure, Robert overreacts and exposes him and the police to danger. Kamper makes a life-changing discovery on election day.