"Charon's obol" was a coin placed in or on the mouth of the deceased. The custom is recorded in literary sources and attested by archaeology, and sometimes occurs in contexts that suggest it may have been imported to Rome as were the mystery religions that promised initiates salvation or special passage in the afterlife. The custom was explained by the myth of Charon, the ferryman who conveyed the souls of the newly dead across the water – a lake, river, or swamp – that separated the world of the living from the underworld. The coin was rationalized as his payment; the satirist Lucian remarks that in order to avoid death, one should simply not pay the fee. In Apuleius's tale of "Cupid and Psyche" in his "Metamorphoses", framed by Lucius's quest for salvation ending with initiation into the mysteries of Isis, Psyche ("Soul") carries two coins in her journey to the underworld, the second to enable her return or symbolic rebirth. Evidence of "Charon's obol" appears throughout the Western Roman Empire well into the Christian era, but at no time and place was it practiced consistently and by all.