The Mystery of Three Quarters: The New Hercule Poirot Mystery

By Sophie Hannah





“One of these things is not like the others… one of these things just doesn’t belong…”


This classic Sesame Street song reflects the puzzle at the center of Sophie Hannah’s new book, the third in her series of continuation novels featuring Agatha Christie’s legendary detective Hercule Poirot. I was unenthusiastic about the first entry, The Monogram Murders, and slightly warmer towards Closed Casket, but The Mystery of Three Quarters is a far more engaging work than its predecessors.


The novel opens with a premise that catches the reader’s attention immediately. A woman Poirot has never met or even heard of before approaches him in a rage, demanding to know why Poirot sent her a letter accusing her of the murder of a man equally unknown to Poirot. Poirot’s explanation that the letter is a forgery is met with disbelief, and the woman leaves angrier than when she came. Before Poirot can make sense of this situation, he meets another man, once again a total stranger to Poirot, who has a received a similar forged letter, and is just as unbelieving of Poirot’s denials as the first woman to accost Poirot.


Soon afterwards, Poirot meets another woman who has also received a similar forged letter, though this lady is far more distraught and much more willing to believe that Poirot is not the person behind the accusation. A fourth and final letter recipient emerges, who treats being called a murderer a jolly joke.


The central metaphor at the center of the book is the “Stained Glass Window Cake,” (better known as Battenberg Cake), a cake consisting of two differently-colored sponge cakes, made of four cuboids arranged and frosted so that every slice creates a square with a two-by-two grid of alternating colored squares. The four squares of cake become Poirot’s chief means of demonstrating the problem he faces in making sense of this twisty case. Poirot is looking for a common thread that links all four letter recipients, but for a long time, no matter what he does, he can only find bonds that link at most three of the four characters. The theories only link at most three characters, and Poirot uses three-quarters of a slice of Stained Glass Window Cake as an image reflecting the fact that one of the four letter recipients is always the odd man out. So what does a suspect not fitting the general pattern mean?   Guilt? Innocence? Or perhaps, some sort of twisted design on the part of the letter writer?


I feel like this is the first of Hannah’s continuation novels that truly justifies the use of Christie’s Poirot. Had Hannah created a completely new detective, not much would have changed. The books would have had precisely the same impacts on me, save for sparing me any discomfort over another author using Christie’s creation. The opening chapters of The Mystery of Three Quarters, however, actually require a character like Poirot. If two angry, arrogant, unlikeable people were to accost a strange detective and accuse him of slandering them, the reader might feel mildly sorry for the wrongly accused detective, but that is all. However, when a deeply familiar, widely beloved character is the subject of this rage… the reader responds on a far more visceral level, deeply resenting the wrong done to one of their favorite fictional friends, and when Poirot is so shabbily treated, the reader is particularly fueled with indignant support for their maligned friend, and the stakes behind the investigation are raised because the inquiry is not just catching a killer, it’s vindicating Poirot himself. Indeed, the entire atmosphere of the book would be watered down immensely without Poirot, or a similarly beloved detective, in the role.


There are a few emotional loose ends at the end of the book. Hannah has done a terrific job of creating some truly annoying or frustrating characters that the reader despises, and a real emotional catharsis would have come by seeing all of the disliked figures get a level of comeuppance at the end, for even the only one who receives literary karmic retribution has that justice tempered by another character’s interventions.   A more satisfying conclusion to a dispute over the ownership of a recipe for Stained Glass Window Cake would also have been appreciated. Inspector Catchpool’s mother is mentioned in the book, and I hope that Hannah develops Mrs. Catchpool and her relationship with her son in more detail in future books.


While The Mystery of Three Quarters is missing the panache of genuine Christie and my qualms about another author writing Poirot mysteries remain unabated, The Mystery of Three Quarters is an absorbing read with a particularly engrossing puzzle at the center, with lots of subtle clues that play fair with the reader. The book will entertain many fans of Christie and Golden Age mysteries.



–Chris Chan