C. S. Friedman’s This Alien Shore is a standalone space-opera/cyberpunk novel.
The Hausman drive gave humanity the stars. It also induced mutations in crew, passengers, and colonists. The mutations thrived in the new colonies, which became known as Variants. A bigoted, xenophobic Earth abandoned its colonies. Two centuries later, the Guerans developed an entirely new method of faster-than-light travel, via ainniq, points that give access to an alien realm governed by unfamiliar laws. The Gueran Guild reached out to all of humanity’s worlds, including standoffish Earth, and rebuilt the interstellar community Earth had cast aside.
Now someone is trying to destroy that community.