“I am sure of it,” he answered.

It was not for me to dispute what he said.  I merely shrugged my shoulders.  Yet, as a matter of fact, I was expecting every moment to find the hand of a gendarme upon my shoulder.  I expected it as the carriage stopped before the restaurant and we crossed the pavement.  I expected it even when two men who were sitting in the anteroom of the restaurant rose up to meet us.  Louis, standing between, performed an introduction.

“Monsieur Decresson and Monsieur Grisson,” he said, stretching out his hand, “permit me to make you acquainted with Monsieur le Capitaine Rotherby, a retired officer in the English army, and brother of the Earl of Welmington.”

The two men bowed politely and held out their hands.  They were both typical well-dressed, good-looking Frenchmen, apparently of the upper class.  Monsieur Decresson had a narrow black beard, a military moustache, a high forehead, pale complexion, and thoughtful eyes.  Monsieur Grisson was shorter, with lighter-colored hair, something of a fop in his attire, and certainly more genial in his manner.

“It is a pleasure,” they both declared, “to have the honor of meeting Monsieur le Capitaine.”

The usual inanities followed.  Then Monsieur Decresson pointed with his hand into the restaurant.

“If monsieur will do us the honor to join us,” he said, “we will take luncheon.  Afterwards,” he continued, “we can talk over our coffee and liqueurs.  It would be well for us to become better acquainted.”

I saw no reason to object.  I was, in fact, exceedingly hungry.  We lunched at a corner table in the famous restaurant, and I am bound to admit that we lunched exceedingly well.  During the progress of the meal our conversation was absolutely general.  All the events of the previous night were carefully ignored.  When at last, however, we sat over our coffee and liqueurs, Monsieur Decresson, after a moment’s pause, turned his melancholy gray eyes on me.

“Capitaine Rotherby,” he said, “my friend and I represent a little group of people who have some interest in the place where we met last night.  We are deputed to ask you to explain, if you can, your conduct,—­your attack, which it seemed to us was absolutely unprovoked, upon an habitue of the place and an associate of our own.”

“There is only one explanation which I can make,” I answered slowly.  “I went there, as Louis will tell you, absolutely a stranger, and absolutely by chance.  Chance decreed that I should meet face to face the one man in the world against whom I bear a grudge, the one man whom I had sworn to punish whenever and wherever I might meet him.”

Monsieur Decresson bowed.

“There are situations,” he admitted, “which can only be dealt with in that manner.  Do not think me personal or inquisitive, I beg of you, but—­I ask in your own interests—­what had you against this man Tapilow?”

“Monsieur Decresson,” I said, “I will answer you frankly.  The man whom I punished last night, I punished because I have proved him to be guilty of conduct unbecoming to a gentleman.  I punished him because he broke the one social law which in my country, at any rate, may not be transgressed with impunity.”