A jogger discovers a horrifically disfigured corpse in a pond at Ostersoll. A few days earlier, the attractive Sophie was drugged and abducted in the park. Is she the killer's next victim? Mysterious text messages are the only clue for detectives Westermann and Hartwig. Then another victim is found. Is the demonic murderer a serial killer? He plays cat and mouse, leaving trails as confusing as the dark carpet of long-gone times that envelops the island.