Melchior's wife Keterlyn witnesses a brutal attack. The life of an unknown young man is saved, but the victim who has lost his memory does not know who he is and how he ended up in Tallinn. A ring found at the scene leads Melchior to the night brotherhood, the bizarre troupe who performed on Fair Day also raises questions. Frightening signs suggest that not only the unknown recovering from the attack is in danger, but also Melchior and Keterlyn, who are treating him. At the same time, the pope's envoy, known as a ruthless witch-hunter, arrives in the city.