“At the Gare de Lyon Ada Mason gets a dinner basket, and, shutting herself into the toilet compartment, she quickly changes into her mistress’s clothes, adjusts two false bunches of auburn curls, and generally makes up to resemble her as closely as possible. When the conductor comes to make up the bed, she tells him the prepared story about having left her maid behind in Paris; and whilst he is making up the berth, she stands looking out of the window, so that her back is towards the corridor and people passing along there. That was a wise precaution, because, as we know, Miss Grey was one of those passing, and she, among others, was willing to swear that Mrs. Kettering was still alive at that hour.”
“Go on,” said Van Aldin.
“Before getting to Lyons, Ada Mason arranged her mistress’s body in the bunk, folded up the dead woman’s clothes neatly on the end of it, and herself changed into a man’s clothes and prepared to leave the train. When Derek Kettering entered his wife’s compartment, and, as he thought, saw her asleep in her berth, the scene had been set, and Ada Mason was hidden in the next compartment waiting for the moment to leave the train unobserved. As soon as the conductor had swung himself down on to the platform at Lyons, she follows, slouching along as though just taking a breath of air. At a moment when she is unobserved, she hurriedly crosses to the other platform, and takes the first train back to Paris and the Ritz Hotel. Her name has been registered there as taking a room the night before by one of Knighton’s female accomplices. She has nothing to do but wait there placidly for your arrival. The jewels are not, and never have been, in her possession. No suspicion attaches to him, and, as your secretary, he brings them to Nice without the least fear of discovery. Their delivery there to Monsieur Papopolous is already arranged for, and they are entrusted to Mason at the last moment to hand over to the Greek. Altogether a very neatly planned coup, as one would expect from a master of the game such as the Marquis.”
“And you honestly mean that Richard Knighton is a well-known criminal, who has been at this business for years?”
Poirot nodded.
“One of the chief assets of the gentleman called the Marquis was his plausible, ingratiating manner. You fell a victim to his charm, Monsieur Van Aldin, when you engaged him as a secretary on such a slight acquaintanceship.”
“I could have sworn that he never angled for the post,” cried the millionaire.
“It was very astutely done—so astutely done that it deceived a man whose knowledge of other men is as great as yours is.”
“I looked up his antecedents too. The fellow’s record was excellent.”
“Yes, yes; that was part of the game. As Richard Knighton his life was quite free from reproach. He was well born, well connected, did honourable service in the War, and seemed altogether above suspicion; but when I came to glean information about the mysterious Marquis, I found many points of similarity. Knighton spoke French like a Frenchman, he had been in America, France, and England at much the same time as the Marquis was operating. The Marquis was last heard of as engineering various jewel robberies in Switzerland, and it was in Switzerland that you had come across Major Knighton; and it was at precisely that time that the first rumours were going round of your being in treaty for the famous rubies.”
“But why murder?” murmured Van Aldin brokenly. “Surely a clever thief could have stolen the jewels without running his head into a noose.”
Poirot shook his head. “This is not the first murder that lies to the Marquis’s charge. He is a killer by instinct; he believes, too, in leaving no evidence behind him. Dead men and women tell no tales.
“The Marquis had an intense passion for famous and historical jewels. He laid his plans far beforehand by installing himself as your secretary and getting his accomplice to obtain the situation of maid with your daughter, for whom he guessed the jewels were destined. And, though this was his matured and carefully thought-out plan, he did not scruple to attempt a shortcut by hiring a couple of apaches to waylay you in Paris on the night you bought the jewels. The plan failed, which hardly surprised him, I think. This plan was, so he thought, completely safe. No possible suspicion could attach to Richard Knighton. But like all great men—and the Marquis was a great man—he had his weaknesses. He fell genuinely in love with Miss Grey, and suspecting her liking for Derek Kettering, he could not resist the temptation to saddle him with the crime when the opportunity presented itself. And now, Monsieur Van Aldin, I am going to tell you something very curious. Miss Grey is not a fanciful woman by any means, yet she firmly believes that she felt your daughter’s presence beside her one day in the Casino Gardens at Monte Carlo, just after she had been having a long talk with Knighton. She was convinced, she says, that the dead woman was urgently trying to tell her something, and it suddenly came to her that what the dead woman was trying to say was that Knighton was her murderer! The idea seemed so fantastic at the time that Miss Grey spoke of it to no one. But she was so convinced of its truth that she acted on it—wild as it seemed. She did not discourage Knighton’s advances, and she pretended to him that she was convinced of Derek Kettering’s guilt.”
“Extraordinary,” said Van Aldin.
“Yes, it is very strange. One cannot explain these things. Oh, by the way, there is one little point that baffled me considerably. Your secretary has a decided limp—the result of a wound that
