The investigator Nora Weiss (Anna Maria Mühe) and her new colleague Ben Salawi (Camill Jammal) are investigating the case of the Lübeck psychology professor Peter Marquart (Hans-Jörg Frey), who was drowned in his own bathtub. A first clue leads her to the 16-year-old student Jessica Steiner (Lieselotte Voß), who posts revealing pictures and videos of herself on her own paid website. Shortly thereafter, a daycare manager is murdered.
Young farmer Max asks his lady-in-waiting all the questions: Does she want to be his first girlfriend? And Michael K. also wants to know: does his visitor have a knack for his cows? After many years, Ulf dares to get on a horse again. Can he really make an impression with his riding skills?
An emergency call is received by the Bremen police, cries for help can be heard. A short time later, the body of a young woman is found in a park. The massive injuries to the dead man's neck pose a particular mystery to Bremen's chief inspectors Inga Lürsen (Sabine Postel) and Stedefreund (Oliver Mommsen). A traumatized eyewitness can only provide investigators with the disturbing clue "vampire". While Inga Lürsen pieced together the clues and clues step by step, Stedefreund got caught up in a feverish whirlpool of mystical superstition.
Amy Silva (Suranne Jones) investigates a murder aboard a nuclear submarine. There are already several suspects and two more dead: a young woman on land, the cook of the "Vigil" on the boat. Parts of the nuclear submarine have been contaminated with a deadly poison and are restricted. There must be someone on board sabotaging the mission. Amy dares a dangerous mission, at the end of which she finds herself in mortal danger.