After spending four months at a psychiatric instutition of youth, Martin returns to Hommelvik. He has forgotten a lot from the last few months. He also cannot reach Rebekka. Then he learns that Rebekka has disappeared, and there's a rumour she killed her cousin. Martin tries to find her, and discovers that dark, dangerous forces are ravaging the town.

Who breaks the curfew and shatters his bedroom window? Who's the mystical girl he has such strange dreams of? And why can't he rid himself of the sick feeling in his chest, which makes him forget to eat?

The Servant of Darkness is the final book in Anne Elvedal's paranormal horror YA trilogy.