The Micronauts, Book 3 — Steve Lyons

The final installment in the Time Traveler Trilogy. Within our own universe lies another universe unknown to us...until now. This is the realm of The Micronauts-a place ruled by the tyrant Baron Karza, whose scientific marvels offer his people immortality, at the cost of their humanity. When Earthman Ryan Archer is thrown into their world, not only are things about to change, but Ryan will have much to do with it....