You'll find this in Deep Navigation.

Yet another one of Alastair's parallel universe, ridicilous nonsense stories.   Utter rubbish, to put it mildly.

I live in hope that he will soon get over this bizarre phase in his bibliography.   Next up in the timeline is The Sledge-Maker’s Daughter, and i think i'll throw my Kindle across the room if there's even a hint on one single parallel universe, let alone an infinite number of them. ( )