On a bitter winter evening in 1356, Matthew Bartholomew, Brother Michael and their book-bearer Cynric arrive in Lincoln. Michael is to accept an honour from the cathedral, and Bartholomew is looking for the woman he wants to marry. It is not long before they learn that the friary in which they are staying is not the safe haven they imagine - one guest has already been murdered.
It soon emerges that the dead man was holding the Hugh Chalice, a Lincoln relic with a curiously bloody history. Bartholomew and Michael are soon drawn into a web of murder, lies and suspicion in a city where neither knows who can be trusted.