A Cologne detective asks Jan Fabel for his help in tracking down the Carnival Cannibal, a terrifying serial killer who kills at the start of the world-famous annual Carnival. Unknown to anyone, Fabel's deputy, Maria Klee, also heads for Cologne to hunt down a different, even more dangerous killer - one with whom she has a score to settle. Taras Buslenko, a Ukrainian special-forces commander, prepares his undercover unit for a black operation into Cologne. Their aim: to end the rule of an ex-pat Ukrainian crime-boss. Three paths converging on Cologne at Carnival at a time when the world is traditionally turned on its head. Fabel once more faces his greatest enemy: the true Master of the Carnival.