Multiple Hugo and Nebula Award winner Joe Haldeman's Camouflage -- about two immortal aliens wandering the Earth in numerous incarnations -- can best be described as a science fiction mystery with all the trimmings of a psychological thriller.
A million years before the emergence of humans, an alien spaceship splashes into the Pacific Ocean. After it comes to rest miles underwater, a creature emerges from the vessel and, after assessing its aqueous environment, drastically alters its appearance in order to survive.
After many millennia of existence in the form of various deep-sea creatures -- sharks, whales, porpoises, schools of fish -- the changeling eventually leaves the safety of the water and enters the world of man. Adopting various human personas -- graduate student, soldier, surfer, circus dwarf, prostitute -- the ever-inquisitive changeling slowly masters the intricacies of human society.
When a strange artifact is discovered seven miles below the surface of the Pacific in the early 21st century, the changeling is inexplicably drawn to it. But so is something else: another, much older, shape-shifting alien. This chameleon's motives for wanting to unlock the secrets of the artifact, however, are far different from the changeling's.
Originally published in Analog magazine as a three-part serial, this novel -- unsurprisingly saturated with a variety of existential philosophies -- is one of Haldeman's fastest and most intriguing reads. With relatively short chapters, three tightly intertwined plotlines, and nonstop action throughout, Camouflage will keep readers furiously turning pages until the very end. Paul Goat Allen