The November theme for the Read Christie 2025 challenge is spies. I’ve already read the recommended book, Cat Among the Pigeons, and most of the suggested alternatives – I don’t want to read Postern of Fate yet as it’s the final Tommy and Tuppence book and I’m working through that series in order – so I looked for one I hadn’t read that featured international intrigue and espionage. The Big Four seemed suitable but I was a bit wary about reading it as it seems to have a bad reputation. I needn’t have worried, though, because although it’s clearly not one of her better books, I still enjoyed it!

The novel is narrated by Arthur Hastings, which is always a good thing – I love Hastings! – and he plays a big part in the story, having adventures of his own, not just as narrator and sidekick to Poirot. The book begins with a man arriving unexpectedly in Poirot’s doorway, appearing feverish and exhausted. Unable to speak, he writes the number 4 several times on a sheet of paper, and when he recovers he explains that he was referring to an international crime ring consisting of the Chinese mastermind Li Chang Yen, an American, a Frenchwoman and a mysterious fourth person known only as ‘the Destroyer’. Together they form the Big Four, a group trying to cause global unrest so that they can take over the world.

The rest of the book takes the format of a series of loosely connected episodes, as Poirot, with the help of Hastings, tries to identify the other three members of the Big Four. Of course, with their own spies and agents in every corner of the world, the Big Four know that Poirot and Hastings are on their trail and set various traps for them, some of which they fall into and some they don’t. Poirot attempts to set traps of his own, but although he manages to identify the American and the Frenchwoman fairly quickly, Number Four proves much more elusive.

I found The Big Four more entertaining than I expected, considering that Christie herself described it as “a rotten book”. It’s understandable why she would feel that way as the book was published in 1927, during a time when Christie was struggling financially and emotionally and had disappeared from her home for several days. She felt she had to force herself to complete this book and the next one, The Mystery of the Blue Train. This also explains the episodic nature of the book, because it was based on twelve previously published short stories which Christie reworked into a full-length novel rather than trying to come up with a completely original idea while she wasn’t in the right frame of mind to do so.

Despite the book’s origins and its silly, far-fetched plot, I think it’s better than some of her later thrillers, such as Destination Unknown, but I can see why it’s not well regarded and it certainly doesn’t feel like a typical Poirot novel. As I’ve said, though, it has Hastings in it, which is always a bonus, and we also get to meet – sort of – Poirot’s twin brother, Achille! It was a fun, undemanding read for me in this busy month of November, but probably not one I’ll want to revisit.