It is based on the Greek myths relating to Orpheus, the legendary musician of divine origin, and his wife Eurydice, the wood nymph. The myths tell of how Orpheus goes to the Underworld (Hades) to search for his wife following her death. He is given permission to lead her back to the land of the living on condition that he does not turn around and look at her during the journey. Orpheus is unable to keep to this condition, and Eurydice is forced to return to Hades for ever.
In the opera, there is a happy ending when Amore, the god of love, brings Euridice back to life and reunites her with Orfeo.
Listen on Spotify to Trionfi Amore ('May Love Triumph') which is sung at the culmination of Act 3.