Marley's ghost recalls the Ghost of Hamlet's father, who returns to warn the living. In Hamlet, the Ghost of Hamlet's father appears at night wearing chains (or armor, depending on the scene), reveals that he is suffering after death, and returns to urge Hamlet to set things right. In A Christmas Carol, Jacob Marley also returns after death, burdened by the chains he forged through greed, to warn Scrooge to change his life before it is too late. The idea of a restless spirit returning with a moral warning was already common in folklore, but Shakespeare's ghost is one of the best-known literary precedents.