At the dawn of the fifteenth century, Tallinn stands on the edge of Christendom. Merchants, monks, knights and pirates all struggle for control of the wealthy city. When the brutally decapitated corpse of a knight is discovered, apothecary Melchior Wakenstede, famed for his brilliant mind, is asked to investigate.

But as Melchior tries to untangle the mystery, he stumbles across truths that many powerful people would prefer stayed hidden... Does he dare to defy them all?