On Earth they had died out 70 million years ago but on Ireta the dinosaurs ruled in all their bizarre splendour, roaming a planet as mystifying as any in the galaxy. And the expedition sent to explore it was trapped within its coils when their relief ship disappeared. Soon the Heavyworlders reverted to type, and as predatory carnivores hunted down their colleagues, only the frozen sleep of cryogenics offered an escape - but for how long?