Exiles at the Well of Souls (Saga of the Well World, #2)

Antor Trellig, head of a ruthless interstellar syndicate, had seized a super computer with godlike powers, which could make him omnipotent. The Council offered master criminal Mavra Chang any reward if she stopped Trellig - and horrible, lingering death if she failed. But neither Trellig nor Mavra had taken the Well World into consideration. Built by the ancient Markovians, the Well World controlled the design of the cosmos. When the opponents were drawn across space to the mysterious planet, they found themselves in new alien bodies, and in the middle of a battle where strange races fought desperately, with the control of all the Universe as the prize.