This virtual night / C.S. Friedman.

When deep-space travel altered the genes of the first interstellar colonists, Earth abandoned them. But some of the colonies survived, and a new civilization of mental and physical "Variants" has been established, centered around clusters of space stations known as the outworlds. Now the unthinkable has happened: a suicide assault has destroyed the life support system of a major waystation. All that is known about the young men responsible is that in their last living moments they were receiving messages from an uninhabited sector of space, and were playing a virtual reality game. Two unlikely allies have joined forces to investigate the incident: Ru Gaya, a mercenary explorer with a taste for high risk ventures, and game designer Micah Bello, who must find the parties responsible for the attack in order to clear his name. From the corridors of a derelict station lost to madness to an outlaw stronghold in the depths of uncharted space, the two now follow the trail of an enemy who can twist human minds to his purpose, and whose plans could bring about the collapse of outworld civilization.