Harper & Row, 1974 - 256 oldal
Imagine an encapsulated city trying to survive in a strange world where a mysterious feature of space-time known as the "optimum" is always ahead, just out of reach - and the city has to keep moving in an attempt to reach it, or a particularly bizarre destruction will face its citizens. Unfriendly people outside the city, and an environment full of hazardous terrains, have to be faced and dealt with. Citizens such as young Helward Mann refer to the landscapes ahead as "the future" and to the landscapes behind as "the past." He joins the other members of the City Guilds in working hard, for the optimum must be followed at any price... This novel contains one of the most famous opening lines and one of the most peculiar and unforgettable scenes in all of science fiction.