In ancient Greek mythology, Orpheus was a gifted musician, able to charm birds, fish and wild beasts with his music, coax the trees and rocks into dance, and divert the course of rivers. His beloved wife, Eurydice, fell into a nest of vipers and suffered a fatal bite on her heel. Orpheus, overcome with grief, played such sad and mournful songs that all the gods wept. Orpheus travelled to the underworld, and with his music softened the hearts of Hades and Persephone, who presided over the dead. They agreed to allow Eurydice to return with her husband to earth on one condition: he should walk in front of her and not look back until they both had reached the upper world. He set off with Eurydice following. As he exited the underworld, he turned to check on Eurydice, but as she had not quite reached the upper world, she vanished forever to the realm of the dead.