Klatchian Mist

An Ankh-Morpork metaphor for a thing that does not exist. In Überwald there is a similar expression: "The Fifth Elephant". (Corgi PB, pp 88-89)

Klatch, everyone knows, is an arid desert country with little moisture, mist, or rain. Add the foreignness of Klatch, where everything is strange, untrustworthy and mysterious and you get a sense of fraud or deceit.

Annotation

Idiomatic in Yorkshire and Lancashire is the phrase Scotch mist for something that is hard to find or does not exist.

The same phrase is also idiomatic in some locales in the following dialectical structure:

"I can't find my [domestic object of some kind]."

"Well, what's that?" (Pointing to it in plain view.) "Scotch mist?"