When a friend from her childhood passes away, Rebecka returns to her home in the outskirts of Kiruna. But as it turns out, everything is not what it seems.

When Rebecka think she's getting closer to solve the murder mystery, she has to go further into the shadows of her childhood past that she has struggled hard to leave behind. At the same time she is beginning to doubt as to where she belongs.

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.