Trier is famous for wine, Romans and being Germany's oldest city. When a body is found, covered in a fungal rot, the local police know they're out of their depth. Fortunately, this is Germany: where there are procedures for everything. Enter Investigator Tobias Winter. With the help of local cop Vanessa Sommer, he links the victim to a group of ordinary middle-aged men - who may have accidentally reawakened a bloody conflict from a previous century. But the rot is spreading, and with the suspect list extending to people born before Frederick the Great, solving the case may mean unearthing the city's secret - and magical - history... as long as that history doesn't kill them first.