The blurb on the back:

VOYAGE OF DISCOVERY

Somewhere in the fabled region called Forwards lay the answers to a 400-year-old secret: Who were they? Where did they come from? Where were they going?

But Forwards was far away, through lands of unimaginable horror. And the answers they sought were the jealously guarded secret of the mysterious Unknowns—a secret so hideous that even those superior beings dared not reveal it ... '   

Roy Complain is a proud hunter in the Greene tribe. Every day he goes into the ‘ponic jungle to hunt wild animals. The tribe moves slowly through the Deadways, a vast network of caverns and corridors filled with jungle. The whole place was once created and ruled by an ancient race known as the Giants, who left mysterioius artifacts and strange writings behind.

Roy’s wife, Gwenny, is kidnapped by another tribe when she accompanies him on a hunting expedition. Now a social outcast, Roy is approached by the tribe’s wizard, who invites him to come on a dangerous quest– a quest to find the ultimate secrets of the jungle.

“we are in a sort of container called a ship,” the Priest tells him, “moving from one bit of the world to another.” The priest’s plan is to take control of the ship.

They may be on a “ship”, as the legends say, but where they came from, and where they are going, is a mystery to them.

Non-stop, Alldiss’ first published science fiction novel, is not the first “Generation Starship” book to have been written. For example , Heinlein also covered this idea in Universe. However, it  uses many new ideas, and introduces themes that Aldiss would return to over the course of his his career– the idea of humans losing their control over nature, the primacy of plants over animals, and the quest to understand our origins.

Non-stop moves at a gallop, and is a thoroughly enjoyable read. It is a good introduction to Aldiss’s science fiction work, and indeed is a good introduction to science fiction in general.