Sir Orfeo as being a parallel dimension to the everyday world rather than the Land of the Dead as in the Greek myth of Orpheus and Eurydice. The ability to move between one world and the other distinguishes the tale as told in its various British versions such as "Sir Orfeo" and the Shetland ballad "King Orfeo" where the captors are envisaged as inhabitants of a parallel fairy domain rather than as the infernal region of the Dead ruled over by Hades as in the Greek myth. Katharine Briggs sees the tale as related in British folk narratives as being equally influenced
Hades left Helen with Theseus' mother, Aethra, and traveled to the Underworld. Hades knew of their plan to capture his wife, so he pretended to offer them hospitality and set a feast; as soon as the pair sat down, snakes coiled around their feet and held them there. Theseus was eventually rescued by Heracles but Pirithous remained trapped as punishment for daring to seek the wife of a god for his own. Heracles' final labour was to capture Cerberus. First, Heracles went to Eleusis to be initiated into the Eleusinian Mysteries. He did this to absolve himself of guilt for killing