For the crime of stealing bread, 14-year-old May receives a life sentence: she must become a Sin Eater - a shunned woman, brutally marked, whose fate is to hear the final confessions of the dying, eat ritual foods symbolizing their sins as a funeral rite, and thereby shoulder their transgressions to grant their souls access to heaven. Orphaned and friendless, apprenticed to an older Sin Eater who cannot speak to her, May must make her way in a dangerous and cruel world she barely understands. When a deer heart appears on the coffin of a royal governess who did not confess to the dreadful sin it represents, the older Sin Eater refuses to eat it. She is taken to prison, tortured, and killed. To avenge her death, May must find out who placed the deer heart on the coffin and why.