Another sf venture from physicist-writer Forward (Camelot 30K, 1993, etc.). This time, a crew of intrepid spacefarers--pilots Rod Morgan and Chastity Blaze, engineer Seichi Takeo, fuel specialist Pete Stewart, biologist Sandra Green, and medic Dan Horning--will be paid a billion dollars apiece to fly to Saturn, where a powerful fuel called ``meta'' can easily be manufactured from the abundant helium in the planet's atmosphere. A billion each? Well, the proposition's risky: Since they'll arrive at Saturn with no fuel reserves, they'll have to make their own meta supply before they can leave! In due course, with their ship suspended in Saturn's atmosphere beneath a giant balloon, meta production begins. But Saturn, they find, teems with airborne lifeforms, one of which is the rukh, a kilometers-wide predatory flying wing. Sure enough, a rukh swallows the balloon, forcing the crew to attach their ship to the creature's back, while their nuclear reactor--their sole power source- -lodges in the creature's gullet. The rukh, an intelligent being, is willing to help--but can they make enough fuel to escape Saturn's gravity before the damaged reactor fries either their host or themselves? Thrilling speculations, sub-par dramatics: Once again, Forward's remarkable ideas run way ahead of his ability to express or dramatize them adequately.