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Described as 'the great novel about conspiracy theories' that takes every great conspiracy theory in history (Knights Templar, Rosicrucians, etc.) and bundles them into one super conspiracy theory

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Referenced when discussing Nazism as a conspiracy theory - 'you read Mein Kampf, Mein Kampf is a massive conspiracy theory'

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Explicitly mentioned as a book written by Michael Taylor about the defence of slavery, described as 'a model of how to write about a network without succumbing to conspiracy theory'

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Tom mentions reading it 'for the first time since school' before Christmas, discussing how Dickens explains the French Revolution as a kind of conspiracy

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Referred to as 'Graham Greene's novel' where 'the agent basically invents a conspiracy where none exists, which then comes true'

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Mentioned as 'John Le Carre's take on it later on' referring to the same plot device as Our Man in Havana where an agent invents a conspiracy