Subble, a government investigator, is sent to interview the three survivors of an Earth mission to the planet Nacre. As he listens to their stories, he begins to piece together what really happened on Nacre and what it means. It seems that each of the three had something special about them, and their uniqueness is what saved them. But, there is even more going on here, and they are all trying to hide something. It is up to Subble to get to the bottom of things and make the correct report to his superiors.
This is actually one of Piers Anthony's earliest books, having been first published in 1968. It's also the first book in a trilogy. It is an interesting book, with the sort of cerebral storyline that has all but disappeared from any descent science-fiction today. Indeed, in many ways, this is more of a thought exercise than it is a work of fiction - examining differences that your physiology has on who and what you are.
Star Wars it isn't, so if you are looking for that kind of story you will probably be disappointed. But, if you are looking for the kind of amazingly different kind of science-fiction that they used to write, then you will no doubt enjoy it immensely.