Labyrinthine, hugely digressive, but curiously engaging arabesque set in 15th-century Cairo, originally published in England in 1983. Balian of Norwich travels through Egypt, apparently as a pilgrim en route to the shrine of St. Catherine, actually a spy in French pay hired to report on the shifting fortunes of the Mameluke dynasty. Once in Cairo, Balian falls prey to an exotic dream illness, the Arabian Nightmare, a nocturnal disease that consumes minds in ever-intensifying fits of delusion. Balian's dreams have verisimilitude, and he dreams dreams within dreams, so it's hard to say where his waking life ends and his sleep begins, or where one dream interconnects with the next. He meets Dirty Yoll the Storyteller, who has reconstructed Balian's dreamlife and is narrating it to an enthralled crowd; or perhaps Balian has merely dreamt that he met Dirty Yoll narrating to a dreamt crowd. Surely the Father of Cats--at the Invisible College of Sleep layers below the streets--knows something about the Arabian Nightmare; but, on the other hand, the Arabian Nightmare, and possibly the whole of Cairo's sick dreamlife, might be a projection of the Father of Cat's diseased mind. When Balian attempts to flee Cairo, he only dreams he's fleeing Cairo, and all the streets circle back towards the center of town; when he attempts to discover the origin of his disease from Yoll, the Storyteller's narrative digresses and ultimately circles back to its center in the manner of Cairo's streets or Balian's dreams. In Limits of Vision (1986), Irwin somewhat unsuccessfully explored the mind of a housewife on the brink of madness, but here his fascination for inner perception, helped along with a delight in Scheherazadian frames and exotic lore, makes for quite a rich experience: a strangely playful construct that, like an intricate Chinese box, delights with each unexpected combination and hidden drawer.