In Medieval Tallinn a famous knight has been murdered. The killer has chopped off the victim's head and stuffed his mouth with coins. The next day, the old wall of the monastery collapses and a series of murders unfolds, which shocks the whole town. The head of a building master who repaired the wall is also chopped off and his mouth is filled with coins, while a priest and a monk of the monastery are poisoned.
Judge Dorn decides to involve Melchior in the investigation of this crime . He discovers that the knight, who allegedly was here by chance, was actually hunting for a mysterious "Prisoner of Tallinn" – for some reason he did not search him from prison, but from a Dominican monastery.
Is there one murderer behind all these crimes, or is someone trying to imitate other crimes and cause confusion? Melchior understands that the key to the secret lies in the question - who or what is this mysterious "Prisoner of Tallinn"?
Movie in Latvian with subtitles in English.