While Head of Homicide for Copenhagen Police Jens Møller comes in for the morning briefing, an investigator reports on a strange case. A homemade submarine carrying a female Swedish journalist and the submarine's inventor has gone missing.

Jens Møller is constantly under pressure from journalists who are chasing news of the case. Meanwhile, rumours and theories abound. Were the Swedish journalist and the accused previously acquainted?

Chief Prosecutor Jakob-Buch Jepsen makes it clear to Jens Møller that they need more firm evidence to bring charges in the case. Otherwise, they risk the accused walking free.