As private detective Steffen Horndeich sits in his garden with his business partner, estate administrator Jana Welzer, they receive an unexpected visitor: Marco Seidel wants to hire Steffen Horndeich to find the murderer of the pop singer Susanna. She was murdered 19 years ago, and Seidel has been in prison for it—innocent, as he claims. Horndeich and Jana take on the case. Seidel's conviction initially seems convincing. However, the two soon encounter inconsistencies: not all the alibis of the other suspects are as solid as first assumed. And who was the stalker who pursued the singer back then? The deeper Horndeich and Jana dig, the more incredible details they uncover. So was Seidel really innocent?.