London, Gollancz, 1989. First Edition. First Impression. Hardback. Lovely copy, signed by the author without inscription. Winner of the 1989 BSFA Award. The seventh of Pratchett's Discworld novels, being the first standalone novel. Examines the themes of quantum physics and power. A fine copy with the slightest of spine leans. The jacket is in great shape. Cover art by Josh Kirby [6417, Hyraxia Books].