"You will pardon me, gentlemen, when you know who I am," said the intruder, and throwing open his coat he showed his tricolour scarf. "I have to make enquiry relative to a dead body that has been found on the line near Brétigny; it probably fell from this train, and perhaps from this compartment, for I have just observed that the safety catch is not fastened. Where did you get into the train?"
The two passengers looked at one another in astonishment.
"What a dreadful thing!" one of them exclaimed. "Why, sir, to-night, while my friend here and I were asleep, one of our fellow-travellers did disappear. I made a remark about it, but this gentleman very reasonably pointed out that he must have got out at some station while we were asleep."
"Quite easily recognised, sir; a man of about sixty, rather stout, and wearing whiskers."
"That tallies with the description. Might he have been a butler or a steward?"
"Then that must be the man whose body has been found upon the line. But I do not know whether it is to be regarded as a case of suicide or of murder, for some hand baggage has been picked up as well: a suicide would not have thrown his luggage out, and a thief would not have wanted to get rid of it."
The passenger who had not yet spoken, broke in.
"You are wrong, sir; at any rate all his luggage was not thrown on to the line," and he pointed to the bundle left upon the seat. "I thought that belonged to the gentleman here, but he has just told me it isn't his."
The official rapidly unfastened the straps and started back.
"Hullo! A bottle of liquid carbonic acid! Now what does that mean?" He looked at it. "Did this bundle belong to the man who disappeared?"
"I don't think so," one of them said; "I should certainly have noticed that Scotch rug; but I did not see it."
"Then there was a fourth passenger in this compartment?" the official enquired.
"No, we travelled alone," said one of the men, but the other dissented.
"It is very odd, and I am not sure about it, but I really am wondering whether someone did not get into our compartment last night while we were asleep. I have a vague impression that someone did, but I can't be sure."
"Do try to remember, sir," the official urged him; "it is of the very highest importance."