The Return Of Nathan Brazil: Jack L. Chalker

Book IV of Saga Of the Well World. The Dreef was a hive-mind, composed of trillions of virus-sized units which infected intelligent beings like a disease, taking over their minds. It was on its way to conquering the entire galaxy - until those with still-free minds fought back, using a weapon so powerful that it wrought havoc with the Well World: the ancient planet sized super-computer that the vanished, god-like super-race the Markovians had built to maintain the form of their entire universe. If the Well World's control of time and space could not be restored, the Universe could vanish like a blown-out candle flame. Only a Markovian could go to the Well World and repair the damage; but there was only one Markovian still known to survive - last seen in human form and going by the name of Nathan Brazil. But no-one knows where he is in the immensity of the galaxy - or if he's even still in human form. The task of finding Nathan falls to she who has done the impossible over and over again - Mavra Chang, one of the few beings ever to escape from the Well World and owner of Obie, possibly the second most powerful computer in the Universe. With those two on his trail, Nathan Brazil could run - but can he hide? Cover art by Clyde Caldwell.