Inside the great golden walls, under the crystal of the huge dome, the air was heavy and damp. The streets were crowded with strange, pyramid-shaped buildings. It had been a long journey for thirteen-year-old Will—from the secret hideout in the White Mountains, the final refuge for the small group who were the only free men left in the world. And now the most dangerous part of the adventure had begun: Will and his friend Fritz were inside the fearsome City of the Tripods.

Their mission: Find out about these creatures who control men's minds. How do they operate, what is their plan for the world they rule? And what chance have free men to over throw them?

Against constant threat of discovery and death, the boys begin to find some of the answers. John Christopher's second book about the world of the future is as taut and compelling as one would expect from this master story teller.

From the dust jacket