Often suffers insults Hera from her husband Zeus. So it was when Zeus fell in love with the beautiful Io and to hide her from his wife Hera, turned Io into a cow. But this thunderer did not save Io. Hera saw the snow-white cow Io and demanded from Zeus that he give it to her. Zeus could not refuse this to Hera. Hera, having taken possession of Io, gave her under the protection of a stock Argus. The unfortunate Io suffered, she could not tell anyone about her sufferings; turned into a cow, she was speechless. Argus, who did not know sleep, guarded Io, she could not hide from him. Zeus saw her suffering. Calling his son Hermes, he told him to kidnap Io.

Hermes quickly rushed to the top of the mountain, where the one-eyed guardian Io was guarding. He put Argus to sleep with his speeches and flute. As soon as his hundred eyes closed, Hermes pulled out his curved sword and cut off Argus' head with one blow. Io was released. But even with this, Zeus did not save Io from the wrath of Hera. She sent a monstrous gadfly. With his sting, the gadfly drove the unfortunate sufferer Io, distraught from torment, from country to country. She found no peace anywhere. In a frenzied run, she rushed on and on, and the gadfly flew after her, every minute plunging its sting into her body; the sting of the gadfly burned Io like red-hot iron. Where has Io not run, in what countries has she not visited!

Finally, after long wanderings, she reached in the country of the Scythians, in the far north, the rock to which the titan was chained Prometheus, He predicted to the unfortunate that only in Egypt she would get rid of her torments. Io raced on, driven by the gadfly. She endured many torments and saw many dangers before she reached Egypt. There, on the banks of the blessed Nile, Zeus returned her to her former image, and her son was born Epaf. He was the first king of Egypt and the ancestor of a great generation of heroes, to which the greatest hero of Greece also belonged, Hercules.