“It is possible, yes. It is certainly possible.”

The doctor looked at him curiously.

“You will pardon me, M. Poirot, but I do not quite understand you.”

“I do not understand myself,” said Poirot. “I understand nothing at all. And, as you perceive, it worries me.”

He sighed and bent over the little table examining the charred fragment of paper. He murmured to himself,

“What I need at this moment is an old-fashioned woman’s hat-box.”

Dr. Constantine was at a loss to know what to make of this singular remark. In any case Poirot gave him no time for questions. Opening the door into the corridor, he called for the conductor. The man arrived at a run.

“How many women are there in this coach?”

The conductor counted on his fingers.

“One, two, three – six, Monsieur. The old American lady, a Swedish lady, the young English lady, the Countess Andrenyi, and Madame la Princesse Dragomiroff and her maid.”

Poirot considered.

“They all have hat-boxes, yes?”

“Yes, Monsieur.”

“Then bring me – let me see – yes, the Swedish lady’s and that of the lady’s-maid. Those two are the only hope. You will tell them it is a customs regulation – something – anything that occurs to you.”

“That will be all right, Monsieur. Neither lady is in her compartment at the moment.”

“Then be quick.”

The conductor departed. He returned with the two hatboxes. Poirot opened that of the maid, and tossed it aside. Then he opened the Swedish lady’s and uttered an exclamation of satisfaction. Removing the hats carefully, he disclosed round humps of wire-netting.

“Ah, here is what we need! About fifteen years ago hat-boxes were made like this. You skewered through the hat with a hatpin on to this hump of wire-netting.”

As he spoke he was skillfully removing two of the attached humps. Then he repacked the hatbox and told the conductor to return both boxes where they belonged.

When the door was shut once more he turned to his companion.

“See you, my dear doctor, me, I am not one to rely upon the expert procedure. It is the psychology I seek, not the fingerprint or the cigarette ash. But in this case I would welcome a little scientific assistance. This compartment is full of clues, but can I be sure that those clues are really what they seem to be?”

“I do not quite understand you, M. Poirot.”

“Well, to give you an example – we find a woman’s handkerchief. Did a woman drop it? Or did a man, committing the crime, say to himself: ‘I will make this look like a woman’s crime. I will stab my enemy an unnecessary number of times, making some of the blows feeble and ineffective, and I will drop this handkerchief where no one can miss it’? That is one possibility. Then there is another. Did a woman kill him, and did she deliberately drop a pipe-cleaner to make it look like a man’s work? Or are we seriously to suppose that two people, a man and a woman, were separately concerned, and that each was so careless as to drop a clue to his or her identity? It is a little too much of a coincidence, that!”

“But where does the hat-box come in?” asked the doctor, still puzzled.

“Ah! I am coming to that. As I say, these clues – the watch stopped at a quarter past one, the handkerchief, the pipe-cleaner – they may be genuine, or they may be faked. As to that I cannot yet tell. But there is one clue here which – though again I may be wrong – I believe has not been faked. I mean this flat match, M. le docteur. I believe that that match was used by the murderer, not by Mr. Ratchett. It was used to burn an incriminating paper of some kind. Possibly a note. If so, there was something in that note, some mistake, some error, that left a possible clue to the assailant. I am going to try to discover what that something was.”

He went out of the compartment and returned a few moments later with a small spirit stove and a pair of curling-tongs.

“I use them for the moustaches,” he said, referring to the latter.

The doctor watched him with great interest. Poirot flattened out the two humps of wire, and with great care wriggled the charred scrap of paper on to one of them. He clapped the other on top of it and then, holding both pieces together with the tongs, held the whole thing over the flame of the spirit-lamp.

“It is a very makeshift affair, this,” he said over his shoulder. “Let us hope that it will answer our purpose.”

The doctor watched the proceedings attentively. The metal began to glow. Suddenly he saw faint indications of letters. Words formed themselves slowly-words of fire.

It was a very tiny scrap. Only three words and part of another showed.

– member little Daisy Armstrong

“Ah!” Poirot gave a sharp exclamation.

“It tells you something?” asked the doctor.

Poirot’s eyes were shining. He laid down the tongs carefully.

“Yes,” he said. “I know the dead man’s real name. I know why he had to leave America.”

“What was his name?”

“Cassetti.”

“Cassetti?” Constantine knitted his brows. “It brings back to me something. Some years ago. I cannot remember… It was a case in America, was it not?”

“Yes,” said Poirot. “A case in America.”

Further than that Poirot was not disposed to be communicative. He looked round him as he went on:

“We will go into all that presently. Let us first make sure that we have seen all there is to be seen here.”

Quickly and deftly he went once more through the pockets of the dead man’s clothes but found nothing there of interest. He tried the communicating door which led through to the next compartment, but it was bolted on the other side.

“There is one thing that I do not understand,” said Dr. Constantine. “If the murderer did not escape through the window, and if this communicating door was bolted on the other side, and if the door into the corridor was not only locked on the inside but chained, how then did the murderer leave the compartment?”

“That is what the audience says when a person bound hand and foot is shut into a cabinet— and disappears.”

“You mean—?”

“I mean,” explained Poirot, “that if the murderer intended us to believe that he had escaped by way of the window, he would naturally make it appear that the other two exits were impossible. Like the ‘disappearing person’ in the cabinet, it is a trick. It is our business to find out how the trick is done.

He locked the communicating door on their side —

“in case,” he said, “the excellent Mrs. Hubbard should take it into her head to acquire first-hand details of the crime to write to her daughter.”

He looked round once more.

“There is nothing more to do here, I think. Let us rejoin M. Bouc.”

They found M. Bouc finishing an omelet.

“I thought it best to have lunch served immediately in the restaurant car,” he said. “Afterwards it will be cleared and M. Poirot can conduct his examination of the passengers there. In the meantime I have ordered them to bring us three some food here.”

“An excellent idea,” said Poirot.

None of the three men was hungry, and the meal was soon eaten; but not till they were sipping their coffee did M. Bouc mention the subject that was occupying all their minds.

“Eh bien?” he asked.

“Eh bien, I have discovered the identity of the victim. I know why it was imperative he should leave America.”

“Who was he?”