Under a stone bridge in the Andernach Castle Garden, the body of a young man is found. The 18-year-old Mario Reschkamp was brutally murdered with numerous stab wounds. Koblenz investigator Franca Mazzari and her colleague Bernhard Hinterhuber take on the case. Many signs point to a crime related to the drug scene, as the victim was well-known as a dealer in relevant circles. Interviews within Mario's friend group reveal further intriguing details. Apparently, he had a weakness for occult practices and for women. One of his many girlfriends piques Franca's particular interest: Davina Kayner. The sensitive girl, who lives alone with her grandmother, has clearly not come to terms with the mysterious disappearance of her mother.