Deep into the dark heart of the medieval Black Sea Pearl, a carefully planned serial murder is taking place.
The story takes place in the prosperous port city of Caffa under the rule of the Republic of Genoa, a key node in East-West trade in the Middle Ages. On one side of this city is a symbol of wealth and power, but on the other side it hides the brutal slave trade and endless evil. Now, a deeper fear is quietly spreading.
A mysterious killer codenamed "S" haunts the streets of Kaffa like a ghost. His (or her) target was clear - the Genoese nobles who had amassed wealth through the slave trade. Every attack was extremely cruel, leaving not only bloody traces but also strange and incomprehensible Tatar characters on the scene, as if a revenge curse came from the depths of the grassland. The Genoa authorities fell into panic and helplessness, and the investigation repeatedly encountered obstacles. It seemed that "S"'s killing game had just begun.
