In The A. B. C. Murders , amateur detective Hercule Poirot solves the crime by uncovering the murderer’s motive. This method is unexpected, because it relies primarily on psychology. Refusing to be convinced that Cust is the murderer, he meets him for the first time in prison. This meeting leads...
In The A. B. C. Murders, amateur detective Hercule Poirot solves the crime by uncovering the murderer’s motive. This method is unexpected, because it relies primarily on psychology. Refusing to be convinced that Cust is the murderer, he meets him for the first time in prison. This meeting leads Poirot him to conclude that Cust is neither the person who wrote him the letters nor capable of picking up young women such as one victim. At numerous points after Cust is arrested, Poirot speculates about his possible motive. Most of the other characters, including the police detectives, assume either that Cust is insane, possibly as the result of a World War I injury, or that he is pretending insanity.
When Poirot has solved the mystery to his own satisfaction, he gathers together the so-called Special Legion, a group of people associated with the victims (chapter 23). He reveals to them first how he solved the crime and second the actual murderer’s identity. Only some of the information he presents was available to the reader and the other characters at the point that Poirot learned it. The perplexing factor of the motive, which is the crucial information allowing him to identify the killer, is only revealed in the course of his speeches.
One serious error that everyone had made, including himself, for a long while, was that the letters to Poirot and the murders were the work of a “madman.” Reviewing his impression of the letters, he realizes they were not written by a madman.
I had assumed, without pausing to consider, that what was wrong with them was the fact that they were written by a madman.
Now I examined them again—and this time I came to a totally different conclusion. What was wrong with them was the fact that they were written by a sane man!
The murders were very carefully crafted, and the letters provide mostly accurate information but some misleading items to throw everyone off the track. The murderer was in effect a serial killer, but he used the additional murders as camouflage for the murder he actually wanted to commit. The true murderer is revealed as Frank Clarke, the brother of victim Carmichael Clarke, who was intent on preventing his brother from remarrying after his critically ill wife died.
The obvious detail, among the many that Poirot lays out, concerns the third letter, which he did not receive. The reason that the letters were addressed to Poirot and not the police was to justify the fact that one of them would go astray, which would be difficult to believe if they were addressed to Scotland Yard. A small error in the address meant that the letter regarding the third, or “C,” murder, that of Sir Carmichael, would go astray, so there was no chance of it being prevented.