Summary from Goodreads:
When a wealthy heiress is murdered, Poirot steps out of retirement to find the killer. As the master detective makes his way through the list of suspects, he finds the solution in an elaborately planned scheme almost impossible to believe.
This is Agatha Christie's first published novel, the first featuring Hercule Poirot, and the first I have read as well. I had an idea of what to expect because I had previously seen a couple of Poirot films - the Peter Ustinov ones. Now that I have read the novel, I have to say that he nails the eccentric Belgian detective.
The story is narrated by Lieutenant Hastings, who is on leave at Styles Court and an old friend of the family. Soon after he arrives, Emily Inglethorp, the matriarch and step-mother of John and Lawrence Cavendish, dies of strychnine poisoning. As the events occur during WWI, Poirot happens to be on exile near Styles Court and, as a friend of Hastings, decides to help solve the case.
I have to admit that I am a little sad that the war background wasn't better explored, but (judging solely from this novel) Agatha Christie's mysteries aren't exactly deep novels. I breezed through The Mysterious Affair at Styles, but couldn't help myself from rolling my eyes extra-high when it came to certain clichéd depictions - Jewish spy, knightly idealistic gentleman, saintly nurse, indomitable and jealous exotic beauty, or stoic and sensible English lady. Cozy mysteries are full of these types, but Christie wasn't the first one to stock up on them. As I read, I couldn't stop thinking about A.C. Doyle's Sherlock Holmes. Even the duo military narrator - eccentric detective has similiraties with that of Watson and Holmes. However, Christie made them distinct from their predecessors: Hastings is way more uptight and full of himself than Watson, while Poirot isn't nearly as aloof or socially awkward as Holmes.
It is a fun novel, but I'm affraid the details won't stick. The mystery itself is a classic whodunit. So classic that I was constantly reminded of the Appointment with Death film - even the solution is similar. The motive is clear (money), the cause is known (poisoning, which I heard it's a Christie's classic), and the array of suspects is varied. I'm usually good at guessing the killer, but, guided but the confused narrator, my suspicions went from character to character without settling. That made it even more of a page-turner, so I'm not complaining.