"In the trade, something between an irritation and a great curiosity. There are not many—perhaps a hundred in all. They are books that are only catalogued, never actually sold. They seem to appear in auction lots and collections, but if you should buy that lot, the book will be missing, and when you complain you will find no mention of it in the detail. A photograph for illustration purposes only will include Mr. Murder Investigates third in the pile, but it is from an old sale. Do you see? Like today. I should have a copy of The Mad Cartographer’s Garden . By every measure I know it is in this shop, and yet I also know that it is not. It is not in this shop, if we were to turn it upside down into the street and check every title on the pavement. In a month from now, someone will offer me a lot containing Five Cardinals of Z , but I won’t be able to secure the collection. Later, I will get in touch with the lucky purchaser to see if they will sell, and find that they have already done so. They will gladly tell me that they enjoyed the story while they possessed it: a brash adventure in which the holy Afric Saint, Augustine"—Neith closes her eyes for a moment. A random example or one drawn from life? Shand doesn’t notice—"takes on a sort of Tarzan role, fighting with his sorceress lover against a magical invasion from the Visigothic west. When I track the next purchaser down with my offer, they will tell me the book is about something quite different. They may be quite irate. In any case, they will have sold it on.