The integral trees - Larry Niven

"Niven has come up with an idea about as far out as one can get. . . . This is certainly
classic science fiction-the idea is truly the hero."-Asimov's Science Fiction Magazine

When leaving Earth, the crew of the spaceship Discipline was prepared for a routine
assignment. Dispatched by the all-powerful State on a mission of interstellar exploration
and colonization, Discipline was aided (and secretly spied upon) by Sharls Davis
Kendy, an emotionless computer intelligence programmed to monitor the loyalty and
obedience of the crew. But what they weren't prepared for was the smoke ring-an immense
gaseous envelope that had formed around a neutron star directly in their path. The
Smoke Ring was home to a variety of plant and animal life-forms evolved to thrive
in conditions of continual free-fall. When Discipline encountered it, something went
wrong. The crew abandoned ship and fled to the unlikely space oasis.

Five hundred
years later, the descendants of the Discipline crew living on the Smoke Ring no longer
remember their origins. Earth is more myth than memory, and no recollection of the
State remains. But Kendy remembers. And just outside the Smoke Ring, Discipline waits
patiently to make contact with its wayward children.