An old, mysterious book and a brewer from the 13th century – and suddenly the door into the world of the dark ages is wide open. Niklas von Hahnfurt sets out to become the best beer brewer of his time. From his Franconian home he comes via Weihenstephan Abbey to St. Gallen, the stronghold of the mediaeval art of brewery. After several pilgrims are killed with poisoned beer, Niklas attracts the attention of the fanatic inquisitor Bernard von Dauerling. A deadly chase begins. His escape brings Niklas to the beer towns Regensburg, Bitburg and Cologne and later the „beer wizard“ even reaches Lübeck and London. But in the end a last „beer duel“ with his archenemy is unavoidably.