M. Bouc said meaningly: “Owing to the circumstances in which it was found, it seems fairly certain that this button was dropped by the man who was in Mrs. Hubbard’s compartment last night when she rang the bell.”
“But, Monsieur, there was no one there. The lady must have imagined it.”
“She did not imagine it, Michel. The assassin of M. Ratchett passed that way—and dropped that button.”
As the significance of M. Bouc’s words became plain to him, Pierre Michel flew into a violent state of agitation.
“It is not true, Monsieur; it is not true!” he cried. “You are accusing me of the crime. Me, I am innocent. I am absolutely innocent! Why should I want to kill a Monsieur whom I have never seen before?”
“Where were you when Mrs. Hubbard’s bell rang?”
“I told you, Monsieur, in the next coach talking to my colleague.”
“We will send for him.”
“Do so, Monsieur, I implore you, do so.”
The conductor of the next coach was summoned. He immediately confirmed Pierre Michel’s statement. He added that the conductor from the Bucharest coach had also been there. The three of them had been discussing the situation caused by the snow. They had been talking some ten minutes when Michel fancied he heard a bell. As he opened the doors connecting the two coaches, they had all heard it plainly—a bell ringing repeatedly. Michel had run post-haste to answer it.
“So you see, Monsieur, I am not guilty,” cried Michel anxiously.
“And this button from a Wagon Lit tunic, how do you explain it?”
“I cannot, Monsieur. It is a mystery to me. All my buttons are intact.”
Both of the other conductors also declared that they had not lost a button; also that they had not been inside Mrs. Hubbard’s compartment at any time.
“Calm yourself, Michel,” said M. Bouc, “and cast your mind back to the moment when you ran to answer Mrs. Hubbard’s bell. Did you meet anyone at all in the corridor?”
“No, Monsieur.”
“Did you see anyone going away from you down the corridor in the other direction?”
“Again, no, Monsieur.”
“Odd,” said M. Bouc.
“Not so very,” said Poirot. “It is a question of time. Mrs. Hubbard wakes to find someone in her compartment. For a minute or two she lies paralysed, her eyes shut. Probably it was then that the man slipped out into the corridor. Then she starts ringing the bell. But the conductor does not come at once. It is only the third or fourth peal that he hears. I should say myself that there was ample time—”
“For what? For what, mon cher! Remember, there are thick drifts of snow all round the train.”
“There are two courses open to our mysterious assassin,” said Poirot slowly. “He could retreat into either of the toilets or—he could disappear into one of the compartments.”
“But they were all occupied.”
“Yes.”
“You mean that he could retreat into his own compartment?”
Poirot nodded.
“It fits—it fits;’ murmured M. Bouc. “During that ten minutes’ absence of the conductor, the murderer comes from his own compartment, goes into Ratchett’s, kills him, locks and chains the door on the inside, goes out through Mrs. Hubbard’s compartment, and is back safely in his own compartment by the time the conductor arrives.”
Poirot murmured: “It is not quite so simple as that, my friend. Our friend the doctor here will tell you so.”
With a gesture M. Bouc signified that the three conductors might depart.
“We have still to see eight passengers,” said Poirot. “Five first-class passengers—Princess Dragomiroff, Count and Countess Andrenyi, Colonel Arbuthnot, and Mr. Hardman. Three second-class passengers—Miss Debenham, Antonio Foscarelli, and the lady’s-maid, Fräulein Schmidt.”
“Whom will you see first—the Italian?”
“How you harp on your Italian! No, we will start at the top of the tree. Perhaps Madame la Princesse will be so good as to spare us a few moments of her time. Convey that message to her, Michel.”
“Oui, Monsieur,” said the conductor, who was just leaving the car.
“Tell her we can wait on her in her compartment if she does not wish to put herself to the trouble of coming here,” called M. Bouc.