Currently the most complex work in Wolfe's oeuvre, The Urth Cycle is located on the immensely ancient world of Urth. Millions upon millions of years of human civilisation have left the planet one vast relic, its geology having long succumbed to layer after layer of archaeological remains. Commercial mines sunk into these strata yield fragments of mysterious, lost ages: ruins, bones, obscure relics with forgotten purposes, and countless indeterminate artefacts. Languishing beneath a sun grown old and red and massive, Urth is dying: its winters are becoming protracted, the stars remain visible throughout the day, and its peoples live among the accretions of cultures barely remembered.

Urth is a world divided by conflict. In a far future South America, the Commonwealth is engaged in a protracted war of attrition with trans-equatorial Ascia, whose armies assail the Commonwealth's mountainous northern border. These invaders are, however, only the servants of powerful Lovecraftian monstrosities which have travelled across space to conquer Urth and enslave its peoples.

Hope is kept alive in the Commonwealth by popular faith in its ruler, the Autarch, and in the legendary, Christ-like Conciliator who came to Urth long ago to prophesy that a New Sun would bloom and rejuvenate the denuded land. The prophet and his prophecy are believed and the populace trusts that the Conciliator's Second Coming will herald the arrival of the New Sun.

The reader is guided through this bizarre world by Wolfe's narrator/ protagonist Severian, who is blessed, or cursed, with a perfect memory. The Book of the New Sun is Severian's memoir, written 10 years after he becomes Autarch, when his apparently faultless recall enables him to record and comment on his youthful experiences with a beguiling clarity.

The Shadow of the Torturer begins with Severian, ignorant of his true parentage, apprenticed to the feared guild of torturers. He has lived all his short life in the guild, learning the ‘art’ of dispensing pain within the confines of the Matachin Tower. Severian's life of drudgery and study is relieved briefly when he secretly saves the life of the rebel warrior Vodalus, rescues the injured fighting dog Triskele, and falls hopelessly in love with Thecla, a ‘client’ condemned to death by torture.