The myth about Juno and her rival Io, is one that speaks of how Jupiter, to protect his mistress from the anger of his wife, turned her into a heifer. Juno, suspicously, ordered Argus, the god with 100 eyes to keep a close watch on her and once Io was immrisoned, Jupiter decided to intervene. He told Mercury to make Argus close all his eyes, and then kill him in his sleep. Cleverly, Mercury began to play his Syrinx, but seeing that Argus wouldn't sleep, he began to tell the tale of the nymph Syrinx and the god Pan who fell in love with her and tried to catch her but instead embraced the beauty and melody of the reeds in which she transformed into. In this way, Argus finally shut his eyes and Mercury cut his throat, releasing Io, who ran until she was returned to her human form and to her father and sisters.