Once, Sheema fell in love with a champion named Edru, who guarded his tribe from the vrakhiri. She took him to the Underworld, so she would have him by her side.
But Edru's sons Edug and Elil would not allow it. So they travelled to the Underworld to get their father back. They faced many foes, but also Andag, the god of war, whom at first they took for a mountain. This amused Andag and he promised to help them. Together, they tracked Sheema down, entered her palace in the land of the dead and demanded that she returned their father. They didn't know that he who has stepped into the Underworld can never return. Only Sheema herself has the power to pass back and forth through the veil.
But the goddess admired their courage and perseverance. She offered to break the rule. 'I won't release Edru,' she said 'but you may return. However not as men, but as the sun and the moon, so that you can watch over your tribe and protect them.' And so Edug and Elil became what we call the golden and silver discs. And they will live in the heavens for all eternity.