Still recovering from a psychological breakdown after her encounter with Mildred's murderer, Rebecka takes a job as a public prosecutor in Kiruna. Meanwhile, Mella investigates the death of an unidentified young woman found in an ice-fishing trailer and asks Rebecka for help.

After her unconventional methods get her fired, Rebecka sinks into another deep depression. But a shocking revelation about one of the mining owners puts her back on the case.

Mella leads an investigation into the drowning of a young diver trapped under ice for a whole winter. But the water in her lungs doesn't match the river in which she was found.

The discovery of another body and the unearthing of an old Nazi airplane near the mountain lake provide Mella and Rebecka more clues to the truth. Rebecka has misgivings about her life with Mans as she grows closer to police dog handler Krister.

Rebecka plans her move back to Stockholm but reconsiders when she and Krister discover the body of a woman brutally murdered. The only witness is the victim's young grandson, now alone and too traumatized to speak.

Despite resigning, Rebecka continues investigating the case, focusing on the victim's father, who was eaten by a bear. Meanwhile, Mella and her team discover the murder weapon in the barn of one of the victim's lovers.