The city is winched along tracks through a devastated land full of hostile tribes. Rails must be freshly laid ahead of the city and carefully removed in its wake. Rivers and mountains present nearly insurmountable challenges to the ingenuity of the city's engineers. But if the city does not move, it will fall farther and farther behind the "optimum" into the crushing gravitational field that has transformed life on Earth. The only alternative to progress is death. The secret directorate that governs the city makes sure that its inhabitants know nothing of this. Raised in common in creches, nurtured on synthetic food, prevented above all from venturing outside the closed circuit of the city, they are carefully sheltered from the dire necessities that have come to define human existence. And yet the city is in crisis. The people are growing restive, the population is dwindling, and the rulers know that, for all their efforts, slowly but surely the city is slipping ever farther behind the optimum. Helward Mann is a member of the city's elite. Better than anyone, he knows how tenuous is the city's continued existence. But the worldhe is about to discoveris infinitely stranger than the strange world he believes he knows so well.

Christopher Priest was born in Cheshire, England. He has published eleven novels, three short-story collections, and a number of other books, including critical works, biographies, novelizations, and children’s nonfiction. His most recent novel, The Separation, won both the Arthur C. Clarke Award and the BSFA Award. In 1996 Priest won both the World Fantasy Award and the James Tait Black Memorial Prize for his novel The Prestige, which was adapted into an Oscar-nominated film by Christopher Nolan in 2006. He has been nominated four times for the Hugo Award, and has won several awards abroad. In 2001 he was awarded the Prix Utopia (France) for lifetime achievement. He has written drama for radio and television, and has had features and reviews in The Times, The Guardian, The Independent, the New Statesman, The Scotsman, The Washington Post, and many magazines. He is married to the writer Leigh Kennedy. They live in Hastings, England, with their twin teenage children.