I am probably the only person in the world who doesn’t know this, but G.K. Chesterton’s The Man Who Was Thursday is an allegory. It is not a mystery, or a thriller, or a comedy (in the genre senses of the words). It literally does not make sense on any level other than the allegorical.
It is important to know this, because otherwise you might be like me and start listening to an unabridged reading recorded off BBC7 under the vague impression that it’s a thriller. And then things start making less and less sense, and you get annoyed, and you decide to just skim the book rather than spend more time with people who aren’t very smart, and then boom! suddenly you’ve got allegory all over you.
Which is a terrible thing to happen when you’re not expecting it.