Prometheus was a titan who was the savior of all mankind. In those days when he had just given fire to men and when he was bound to the rocky peak of Caucasus, he encountered a strange visitor in the form of a heifer (a young cow; one that has not had a calf). It had apparently strayed there and began to speak madly with the voice of a young maiden. She cried:.
This that I see ".
A form storm-beaten.
Bound to the rock.
Did you do wrong?.
Is this your punishment?.
Where am I?.
Speak to a wretched wanderer.
Enough "I have been tried enough ".
My wandering "long wandering.
Yet I have found nowhere.
To leave my misery.
I am a girl who speaks to you.
But horns are on my head.
Prometheus recognizes her as Io, daughter of Inachus, and he told her that he knew of her trouble because of a God who had fallen in love with her and how because of that, she had to suffer Hera's wrath as consequence.
Io asked him who he was and Prometheus introduced himself as "Prometheus who gave mortals fire-.
They started to converse openly to one another and Io told him about how Zeus himself had fallen in love with her and how during her sleep, she would have visions and in those visions he tried to woo her with gentle words. Yet still, far greater than his love for the maiden was his fear for Hera's jelousy. He would conceal him Io from the sight of others with a mist "a great veil of dark clouds that hid them well. But Hera was suspicious and shhe commanded and ordered the cloud off. But Zeus ws quick and cunning and immediately before they were revealed to Hera, he transformed Io into a lovely white Heifer. Hera thought that the Heifer was beautiful and asked Zeus to make her a present of it. Zeus could do nothing but succumb to her wishes lest that she would find out about them. He gave Io to her reluctantly and Hera knew perfectly well how to keep the thing away from him.