Metamorphoses Book 15: Hippolytus
Hippolytus explains how he was framed for incestuous seduction by his stepmother, and so he was exiled from his home. On his way to a new land he was driving his chariot near the ocean and a horned bull rose from the water. His frightened horses went crazy, and he was tangled in the reins. He was dragged to death, but Aesculapius restored him to life. Apollo changed the young man's name to Virbius so that no one would be jealous that he'd been given a second life. Virbius became a local deity who tends Diana's shrine.
Hippolytus' story didn't quiet Numa's wife any, so Diana made the woman dissolve into a pool of water.