Between 1991 and 1998 there was an undercover war waged in Great Britain between two warring factions of a secret cabal. At various points one faction or the other controlled the so called "Ministry of Magic" main function of which is to enforce the secrecy of the whole conspiracy.

I know it is true because I read it in a book. Except it is not, it is completely made up and none of it is true. One can accidentally stumble upon true statements in the book. For example there is indeed a Kings Cross station both in the real world London and the fictional one.

> You can say the same thing about any book ever written,

Not really. There are this class of books called "nonfiction" where the stated goal of the author is to write true things. For example if you say "Socialism was already in the air in 1870s Russia, I read it in Peter Kenez's A History of the Soviet Union from the Beginning to the End" that would be not mistaken.

This is an excessive level of pedantry, even for HN.