G.K. Chesterton's The Man Who Was Thursday: from thriller to Narnia

Part of my reading over the Christmas break...
The Man Who Was Thursday begins as a police-thriller, as a hunt for anarchists. This is Joseph Conrad’s territory in Under Western Eyes or The Secret Agent, where Conrad has a pitiless, sardonic view of the shabby grandiloquence and moral illusions of the anarchist and the secret policeman. Chesterton, for his part, unveils a nice irony, as one by one each member of the anarchists' council is revealed as a secret policeman. At first this is the source of an elegant, uncanny effect, but as each perceived antagonists is uncovered as a hero, the technique becomes predictable, tiresome even.
Incrementally, the novel switches genre, turning from the uncanny to the fantastic to allegory, as Sunday, the ultimate antagonist, is revealed as The Sabbath, God: it’s like travelling from a spy-thriller into Narnia, when the anarchist’s chairman is unmasked as Aslan. This is a provocative, innovative, even perplexing, turn, but I must admit to the feeling of being sold an elaborate sermon in the guise of a narrative.