Beautiful women who appeared harmless and sang a beautiful song to passing sailors, only to prove vicious and bloodthirsty when the sailors ventured too close. The Greeks often said that the Sirens were the daughters of the river god Achelous, while the Romans named their father as Phorcys. In the Argonautica, Chiron warns Jason that Orpheus will be instrumental on his journey, and Orpheus later saves all of Jason's crew (save Butes) by playing his lyre when they pass the Sirens to drown out their beautiful and alluring song. Odysseus also encountered the Sirens, tying himself to the mast of his ship so that he could safely hear their song while his crew plugged their ears with beeswax, on the advice of the sorceress Circe.