Hal Clement

The return of Barlennan Dhrawn was a giant rockball, more than 3,000 times the mass of Earth. Perhaps a planet, perhaps a nearly dead star, the 17 billion square miles of mystery cried out for investigation. But its corrosive atmosphere and crushing gravity assured that no human would ever set foot on its surface. Those hardy, caterpillar-like Mesklinites, on the other hand, were ideally suited to explore Dhrawn, and their leader certainly knew a good deal when he saw one. So Barlennan, a shrewd sea captain if ever there was one, struck a sharp bargain with the Earthmen for his services in leading the expedition. But the humans might not have been so pleased with their side of the bargain, if they had known that Barlennan had plans of his own for Dhrawn The stunning sequel to the classic SF novel Mission of Gravity.