Alex leaves Thomas in the hospital and meets the Sin Eater, William Eden, at St. Peter's Cathedral who explains that he has been a Sin Eater for centuries, taking over for an earlier Sin Eater (a Carolingian priest) who ate the sins of Eden's brother. Eden is very charismatic and talks with Alex about the priest's desires, and Alex admits he wants Mara. He then goes and presumably tells Mara this, and they make love. Afterward, Alex leaves Mara asleep and goes to Eden, who tells Alex that he is tired and ready to die and asks Alex to take his place. Alex has the dagger with him, but is curious and so doesn't use it to kill Eden. Instead, he assists Eden with a sin eating ritual. But in the end, Alex refuses Eden's offer because he has decided to leave the priesthood to be with Mara.