"So you travelled in a first-class compartment in the slow train from Paris to Luchon on the night of the 23rd of December, and in that compartment there was the luggage of a traveller whom you did not see—who may not have been there?"
"Yes," said Gervais Aventin, and, as the detective sat silent for a moment, he enquired: "Is my information too vague to be of any use to you?"
Juve was wondering inwardly why the dickens Etienne Rambert was not in that compartment when, according to the depositions of the guard, he must have been there; but he said nothing of this. Instead, he said:
"Your information is most valuable, sir. You have told me everything I wanted to know."
Gervais Aventin displayed still more surprise.
"Well," he said, "by way of return, M. Juve, tell me something which puzzles me. How did you know I travelled by that train that night?"
The detective drew out his pocket-book, and from an inner pocket produced a first-class ticket, which he held out to the engineer.
"That is very simple," he replied. "Here is your ticket. I wanted to know exactly who everyone was who travelled in that first-class compartment, so I sent for all the first-class tickets which were given up by passengers who left the train at the different stations. That's how I got yours: it had been issued at Vierzon, the station where you got in, so I interrogated the clerk at the booking-office who gave me a description of you; then I sent down an inspector to Vierzon to make discreet enquiries, and he got me all the information I required. All I had to do then was to write and ask you to come here to-day; and the regrettable story of your broken relations with the lady was an ample guarantee to me that you would be punctual at the appointment!"