"You will proceed to the Grosvenor Hotel in London, and from there will keep the surveillance I have indicated. Remain there until you hear from me. Report progress frequently--at least every other day--in the personal column of _The Times_." I could scarcely refrain from smiling as I turned from the vivacious Frenchwoman--a Parisian in every detail of her _chic_ appearance--to Henri Aubert, who was to be our colleague in the undertaking we had in hand. Aubert was a sad-faced, rather melancholy looking middle-aged man, with a face from which every shred of intelligence seemed to have vanished. He looked, indeed, exactly like one of those middle-class nonentities, colourless and featureless, who, by the mysterious workings of the mind of the great god Democracy, manage to get themselves elected as municipal councillors, or by superhuman endeavour rise to the position of advocate--and never do any good. But behind his unpromising exterior, which, in fact, was one of his chief assets, since it practically freed him from any possibility of suspicion, was a keen intelligence, trained in every detail of our craft, a patience that knew no wearying on the trail, and a judgment which closed like a steel trap on the essential factor in a complicated situation, and, once having secured a hold, never let go. I knew him well and esteemed him highly, and he possessed the entire trust of the astute Armand Hecq, a trust difficult to win, but, once won, fully and freely given. To Aubert I explained the situation as fully as I could, and, though I knew him to be a model of circumspection, I ventured on a hint of the extreme care and discretion necessary in the delicate affair if we were to succeed in tracing the source of Cauvin's mysterious rise to sudden wealth. He listened to me with a ghost of a smile on his thin lips, but he was evidently piqued. "Perhaps, Monsieur Sant, someone has been telling you I am a confirmed babbler?" he said dryly; and I laughed; the idea of Aubert "babbling" had its humorous aspect. "I think we understand each other, Monsieur Aubert," I said. "I don't mean to cast any reflections on your discretion. But you know the people we have to deal with." "Quite well, monsieur," replied Aubert, with a real smile this time. "We have a difficult job before us. They have a dangerous gang over in England just now. Pierre Gartin was murdered there only last week--shot in a street row unquestionably got up for the occasion. Of course the assassin escaped in the crowd. I think we had better take our revolvers." He spoke as coolly as though his revolver were his umbrella. I was startled. Pierre Gartin was one of the most capable men we had, and I knew he had been engaged on a piece of work very similar to that which we had in hand. In my absence I had not heard of his death. "No, I had not heard," I replied. "But I agree with you that our revolvers might be useful."