Four Lords of the Diamond series By Jack L. Chalker

The Confederacy of the Galaxy is a Utopian society and perfectly safe is it? The top detective/assassin is asked to do the impossible. The Confederacy knew that making everyone equal, bred to a job, would kill humanity, so the brilliant criminal minds went to the Diamond. An alien threat was traced back to the Warden Diamond, the perfect prison. All four planets in the Diamond are infected wit a strange submicroscopic organism that invade every molecule in the body. But some trace element is needed to for their survival, they can not leave the system without dieing. If they die so does the host. In order to find the alien threat, the agent needs to be in four places at once and be imprisoned on the planets as well. The Metron Process allowed this one agent to be four places at once.

I love the series, it is a great sci/fi that is a mystery to unravel. It is mind warping, the way each time the agent see himself live a life through each surrogate. I rate 4 to 5, and PG-13.