The Citadel of the Autarch (The Book of the New Sun #4)

The Citadel of the Autarch (The Book of the New Sun #4)
Volume Four of the Book of the New Sun.
Severian the Torturer continues his epic journey across the lands of Urth, a journey as fraught with peril as it is with wonder. Exiled from his guild he is an outcast, but his travels are woven with strange portents. The Claw of the Conciliator, relic of a prophet and promise of a new age, flames to life in his hands. He carries the great sword Terminus Est, the Line of Division. The dwellers in the deep waters offer him a kingdom under the seas. And he is hunted and driven by terrors from beyond Urth.
Now all his travels move him inexorably toward a grander fate, a destiny that he dare not refuse. For a devouring blackness gnaws at the heart of the Old Sun, and the fate of Urth rests in the return of the Conciliator, the New Sun long foretold.