Exciting entertainment in the colorful historical city of Cologne! Ivo vom Spiegel had forbidden him to return to Cologne - yet Arndt van Doorne comes back to collect his share from a brothel. He pays for it with his life. When Mats Schlyffer is found next to his corpse with a bloody knife, it becomes clear to the judge Endres Overstoltz: the murderer is the knife grinder. However, he cannot remember anything, and there are several other suspects who could have a motive to kill Arndt. Alyss begins to investigate and uncovers a shocking truth...