To Reign in Hell, The Exile of Khan Noonien Singh is the 3rd and final book in the Eugenics Wars series, and they saved the best for last!
This book chronicles the years that Khan and his band of genetically enhanced followers spent on Ceti Alpha V, after they were exiled there by Captain James T. Kirk. Kirk, Spock, Sulu and McCoy, with nothing better to do while Enterprise-A remains in spacedock being refitted, take a trip to Ceti Alpha V. Jim is still haunted by Kahn, the death of his son, and the events that lead up to the tragedies surrounding the Genesis effect. He hopes that by exploring the planet, some sense of what drove Khan to madness and revenge will be revealed.
Beaming down, they find a barren wasteland, hostile conditions and the barest remains of the "camp" of Kahn's community. And they find a cave.
What is revealed in the cave is shocking - Kirk and Company are takens completely off guard and as the story unfolds, it is obvious that a master Star Trek storyteller is at work. Greg Cox spins quite the tale of what happened on Ceti Alpha V. And how the events turned an incredibly superior being into a raving and cruel despot intent on only one thing - revenge.
The tale of survial against all odds, a real love story, betrayal, sacrifice and heroism are all developed within the confines of camps, caves and cargo containers. If you are serious about your Star Trek history and want to read a book that stays true to the vision of "The Great Bird" and the Original Series, then you have to read not only this one, but the first 2 in the series as well. Greg Cox has done an excellent job of taking the reader back to the good old days of the "real" Star Trek, and I wouldn't have it any other way!
Title: To Reign in Hell