Investigator Lennox just can't stay out of trouble. Lennox is looking for legitimate cases — anything's better than working for the Three Kings, the crime bosses who run Glasgow's underworld. So when a woman comes into his office and hires him to follow her husband, it seems the perfect case. And, unusually for Lennox, it's legal. But this isn't a simple case of marital infidelity. When the people he's following start to track him, once more Lennox must draw on the violent, war-damaged part of his personality as he follows this trail of dead men and broken hearts.

The Cologne police know a woman is going to die. They know the day it will happen. And they're powerless to stop it. They call on an outside expert: Jan Fabel, head of Hamburg's Murder Squad and Germany's leading authority on serial killers. Fabel is on the point of leaving the police for good, but Carnival in Cologne is a time when the world goes crazy, and he is drawn into the hunt for the Carnival Cannibal. What he doesn't know is that he is on a collision course with a crack special forces unit from Ukraine and a disturbed colleague with a score to settle. Fabel finds himself on a trail of betrayal and vengeance, violence and death. And once more he faces his greatest enemy. The true Master of the Carnival.