Dining with M. Bouc and Dr. Constantine, Poirot announces that he’s discovered Mr. Ratchett’s real name: Cassetti, the man responsible for the murder of Daisy Armstrong. Two respected and wealthy Americans, Colonel Armstrong and his wife Sonia, had a daughter named Daisy. When Daisy was three-years-old she was kidnapped and held for ransom.
The shady and malevolent impression that Ratchett made begins to be confirmed as Poirot identifies his true identity. Even Mrs. Hubbard’s wild claim that Ratchett was a murderer gains more credence.
Although her parents paid the ransom, Daisy was found dead a little while afterwards. The discovery broke the young couple. Mrs. Armstrong had been expecting another baby, but she experienced a miscarriage and died. Her husband, destroyed by grief, committed suicide.
Poirot also mentions a French or Swiss nursemaid to Daisy Armstrong. After the kidnapping, the police questioned her so harshly that she too committed suicide. After her death, she was completely cleared of any suspicion.
Poirot describes a curious effect of the Armstrong crime: that it dooms everyone involved, even a nursemaid employed by the Armstrongs. The murder destroyed not just the family, but the household as well.
The authorities located the leader of the gang who kidnapped Daisy, a man named Cassetti. His guilt was certain. As Poirot remarks, “Cassetti was the man.” But he escaped justice on a technical inaccuracy. Poirot concludes that the murdered Mr. Ratchett was actually this Cassetti from America, having fled to Europe and changed his name. Given the scale of his crimes, neither Poirot nor M. Bouc can “regret” that he’s dead.
This chapter establishes the certainty of Cassetti’s, later Ratchett’s, guilt. In a mystery, the lead detective is the primary source of truth, and Poirot is known to be careful and talented. He’s not certain of much, but he’s certain that Cassetti was guilty, and that his escape was a damning failure of justice. Tellingly, both Poirot and M. Bouc think his death is no great tragedy, but they’re now in the position of investigating a victim whose murder may have been justified.