Land and Overland — twin worlds a few thousand miles apart. On Land, humanity faces a threat to its very survival — an airborne species, the ptertha, has declared war on humankind, and is actively hunting for victims. The only hope lies in migration. Through space to Overland. By balloon. The Ragged Astronauts — first volume in an epic adventure filled with memorable characters, intense action, engaging notions, exotic locales. Won BSFA Award for Best Novel in 1987

Twenty-three years ago, the inhabitants of Overland left Land to escape the Plague. In this sequel to The Ragged Astronaut, the survivors of Land bring an ultimatum—submit or die of the Plague

The concluding volume of the trilogy which began with “The Ragged Astronauts” and “The Wooden Spaceships” finds the twin worlds of Land and Overland facing a strange new threat. Bob Shaw’s previous novels have earned him a world-wide reputation and he has won the British Science Fiction Award