The young Isenhart grows at the castle guards to Laurin. Together with his friend Konrad he receives all the privileges of nobility. But it happens a cruel murder: Anna Isenhart's great love is brutally murdered - in her breast a gaping hole in her heart is missing. Isenhart vows to bring the murderer to the track. When he witnesses a murder further, having the same profile, he makes the acquaintance of Henning and his foster father, Gunther Medicus. Isenhart is fascinated by Henning, who appears to him in many ways similar: educated, interested, a pioneer of his time! Together they set off on the hunt for the killer and find incomprehensible: The murderer is a genius - and he is very close to them ...

In the middle of century XII much of the European territory is ruled by the Holy Roman Empire and violence and cruelty are the order of the day. Several German regions are terrorized by a dangerous murderer who is dedicated to kill young girls. Therefore, Isanhart and Laurin, his faithful companion in arms, will travel from end to end of the old continent to hunt the ruthless criminal.