When a famous knight is brutally murdered, the lord of the court commissions the young apothecary Melchior, who is rumoured to be able to talk to the dead, to investigate. To his surprise, the clues lead to a monastery.

After the night watchman is haunted by a terrible ghost, he falls to his death from the tower. In addition, several people die in suspicious accidents, the investigation of which Melchior takes in hand.