The March Hare Network — Jack L. Chalker

GO ASK ALICE
Time after time, life after life, Cory Maddox was being incarnated into worlds he found both familiar and strangely different. And it was only in his latest incarnation that, for the first time, Cory brought along knowledge, skills, and memories of his previous existence--memories of cold betrayal, memories that told him that nothing he saw, nothing he felt, could be trusted. Nor could he trust his companions; others who, like himself, kept moving from life to life, intent on gathering enough power to escape the endless cycle.
But it was only with the help of those companions that Cory could develop the technological means to peer beyond the veil of reality--to the system that controlled all existence, where perhaps he could glimpse the shadowy figures whom he was sure were manipulating reality...if what he was experiencing actually was reality.
Time was running out. His memories gave him an advantage over the others, but he would have to act quickly and surely if he were to discover the truth--before truth itself could no longer be trusted...