The Jewel of Bas, by Leigh Brackett (epub/Kindle)
There was a boy-God, sleeping through eternity. And there were his "Stone of Life" and the androids he had created of matter and energy. And there was a world that was to die from the machinations of the androids' diabolic minds. There were Mouse and Ciaran to stem the death-flood—two mortals fighting the immortals’ plans for conquest.