Ten days after lawyer Anne Dragsholm was found dead at a WWII memorial, the police have her husband in custody for her murder. But the chief of investigation calls on Sarah Lund, who has transferred away from the crime squad, to return to Copenhagen to look over the case. Meanwhile, a young politician is made minister of justice after his predecessor is incapacitated, and a convict seeks parole from a detention facility to be with his wife and child

The murder of another former soldier, David Grüner, prompts inquiries into his and Raben's army squad and a particular event during the group's Afghanistan mission a few years before. Lund and Strange track down one of the remaining members in a remote Swedish island. Buch is under pressure from above to cave to the right wing's demands about banning Islamic organisations, but new information about former minister Monberg's relationship with one of the victims makes him weary of acting too hastily.

Lund demands that the grave of the dead soldier Per K. Møller be dug up, but her theory that the coffin is empty is proven wrong. She is suspended from the investigation and takes time to attend her mother's wedding until developments bring her back into action. Buch brings his assistant Karina Munk back after she resigned, despite permanent secretary Plough's objections. They pay a visit to former minister Monberg, who has gained consciousness at the hospital, to find out what he knows about the ongoing case.

Lund and Strange return from Afghanistan with their findings, though Brix has become convinced of the guilt of officer Bilal, who has run away with Louise Raben as his hostage. Buch has been held overnight by the police, but returns determined to bring down the government he is part of. Secrets are uncovered at the ministry and in the military, revealing a conspiracy to conceal vital information. Lund puts together some pieces of her own, and it comes to a lethal confrontation with the killer.