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

This is Book One of the Epic Tetralogy, The Four Lords of the Diamond. Aliens are spying on Earth from one of the four worlds that make up the Warden Diamond. But it is impossible to send agents to any of the four worlds because of unique microscopic symbionts that make it impossible for visitors to leave the Diamond. Seeking a unique solution, each of the four worlds making up the Diamond is sent a person whose mind has been stripped of everything and who is now controlled by an agent of the Confederacy. Lilith is the first planet to be visited. Here, Cal Tremon, stripped of his own personality, must overcome incredible odds and survive not only the incredible perils of the foreign planet but his own controllers as well. 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