Richard Dadd in Bedlam & Other Stories - Alan WallSecker & Warburg, 1999, Paperback.
A detective has to unexpectedly return to London. There he must learn to read the old city anew in the light of the cryptic clues and arcane allusions planted by an apparently murderous sect. He finally discovers how to decipher what is laid before him in a fresh light, understanding in the process how the streets he thought he knew so well are themselves spelling out an ancient form of sacrifice. 226pp.