Lilith: A Snake in the Grass (The Four Lords of the Diamond, Vol. 1)

Somewhere, from among the four human settled worlds of the Warden Diamond, hostile aliens were spying on Earth. But no agent could be sent to investigate and report back. All trips to the Warden worlds were one-way. There a microscopic symbiont called the warden bug invaded all life forms, after which life became impossible outside the Warden system. That called for extraordinary means, of course. One agent was chosen, then four men were stripped of their minds and personalities, and his was imposed upon them. Hooked up properly, he could then receive their report, without ever leaving safe territory. On Lilith people with strong wills manifest the ability to sense and communicate directly with the warden bug. These sorcerers or Sorcs have tremendous power and makeup the political spetrum of the planet. Cal Tremon's mission was Lilith. Assassinate the reining Lord and find evidence of an Alien presence. Somewhere, from among the four human-settled worlds of the Warden Diamond, hostile aliens were spying on Earth. But no agent could be sent to investigate and report back. All trips to the Warden worlds were one-way. There, a microscopic symbiont invaded all life forms, after which life became impossible outside the Warden system. The same organism destroyed any form of machinery, so no message could be beamed back by normal means. That called for extraordinary means, of course. One agent was chosen, then four men were stripped of their own minds and personalities, and his was imposed upon them. Hooked up properly, he could then receive their reports, without ever leaving safe territory. Each man was assigned one world to conquer. His mission was first to find the Overlord of that world and kill him, then to take over his link with the aliens. Of course all this must be done with no help beyond his own naked ability... This first book of Jack Chalker's epic tetralogy deals with Cal Tremon, who was sent to Lilith, a planet that was a paradise - but a paradise designed in hell! -from the back cover