At the heart of the story is a student who accuses her brother of murdering another student. The next morning, Maria's body is actually recovered from the fjord. Investigative duo Klaus Borowski and Sarah Brandt find clues as to why Julia's brother could have committed the crime, but Julia's betrayal cannot be explained by the commissioners. Only when they discover that she has secretly converted to Islam does light seem to be slowly coming into the dark. But Borowski and Brandt are not alone in their research: the state protection department at the state criminal office around head Kesting apparently pursues its own unscrupulous interests.