rted in the papers, in which I discreetly made it known that the
police wanted to get into communication with all the passengers who
travelled first class, in the slow train from Paris to Luchon, on the
night of the 23rd of December last."

This time the young man looked anxious.

"Great Scott!" he exclaimed, "are you in the employment of my future
father-in-law?"

Juve burst into a roar of laughter.

"First acknowledge that you did travel by that train on that night: that
you got into it at Vierzon, where you live and where you are going to be
married; and that you were going to Limoges to see a lady--and that you
did not want your fiancee's family to know anything about it."

Gervais Aventin pulled himself together.

"I had no idea that the official police undertook espionage of that
sort," he said rather drily. "But it is true, sir, that I went to
Limoges--my last post before I was appointed to Vierzon--to take a final
farewell to a lady. But since you are so accurately informed about all
this, since you even know what train I went by, a train I deliberately
chose because in little places like Vierzon so much notice is taken of
people who travel by the express, you must also know----"

Juve checked him with a wave of the hand.

"A truce to jesting," he said; "excuse me, sir, I was only amusing
myself by observing once more how quickly decent people, who have a
little peccadillo on their conscience, are disturbed when they think
they have been found out. Your love affairs do not matter to me, sir; I
don't want to know if you have a lady friend, or not. The information I
want from you is of a very different nature. Tell me simply this: in
what circumstances did you make that journey? What carriage did you get
into? Who travelled with you in that carriage? I am asking you because,
sir, I have every reason to believe that you travelled that night with a
murderer who committed a crime of particular atrocity, and I think you
may be able to give me some interesting information."

The young man, who had been looking grave, smiled once more.

"I would rather have that than an enquiry into my defunct love affairs.
Well, sir, I got into the train at Vierzon, into a first-class
carriage----"

"What kind of carriage?"

"One of the old-fashioned corridor carriages; that is to say, not a
corridor communicating with the other carriages, but a single carriage
with four compartments, two in the middle opening on to the c