When Shrewsbury's goldsmith is robbed and left for dead, drunken locals decide the guilty party must be Liliwin, an itinerant juggler who was performing at the wedding feast of the goldsmith's son. The mob pursues the young man through the streets to the abbey where he frantically seeks the sanctuary of the altar. Cadfael believes Liliwin is innocent, but his search for the truth leads to the discovery of an even deadlier sin.