An attendee at an angel seminar is found in his hotel room, beaten to death. Initially, suspicion falls on fellow seminar attendee Hanne Wegener, who has been missing since the murder. Chief Inspector Carl Sievers apparently knows her from his past, but he is not willing to confide in his fellow officers Hinnerk Feldmann and Ina Behrendsen. Feldmann is left with no other option but to sign up for the angel seminar and investigate the attendees while undercover.