Somehow I could not dismiss the subject of the perfume from my mind; why, I cannot exactly tell, for I could not see precisely the bearing of the card on the problem I had to solve. Was the perfume verbena or scented geranium, and had the card any special significance? Next day, in Marseilles, I entered the shop of one of the leading perfumers in the Cannebiere, and asked the young lady assistant whether she could identify the perfume for me. "Certainly, monsieur," she said without hesitation; "that is geranium." "Are you quite sure," I asked, "that it is not verbena?" "Monsieur shall decide for himself," was the ready reply, and the girl at once fetched samples of both perfumes. A single test was enough to show that she was correct. And then, recognising the purpose of the card, though she could not speak English, she practically duplicated Doris's remark. "Is it not unusual, monsieur, to scent a wedding card?" That set me thinking furiously. It was quite possible that Doris might have made a mistake about a point of social etiquette. But here was a young Frenchwoman corroborating her in quite a dramatic fashion. "It is unusual; I suppose they are peculiar people," I replied as I left. It is one of the penalties of contra-espionage work that one becomes almost morbidly interested in the seemingly trivial. One of the first lessons to be learnt is that nothing is so small that it can be safely neglected. There were, it was obvious, many ways by which the card might have become accidentally impregnated with the perfume. But my intuitive suspicions grew ever stronger, and at last I found myself convinced that there was "something in it." In one particular, at any rate, the card was of first-rate importance. Try as we would, we had failed entirely to connect Cauvin with anyone in England. We were morally certain that he must be receiving messages and money in some subterranean way, but it was certainly not through the post, and up to the present we had failed to find, among his big list of acquaintances and friends, anyone whom we could reasonably suspect of being in touch with the Hidden Hand across the Straits of Dover. But there were many possible channels of communication through neutral countries, and obviously we could not stop them all. Now, with the aid of the wedding card, it seemed possible, always assuming the card to be genuine, that I might be able to locate one person at least in England who was upon extremely friendly terms with our wealthy suspect. That chance, at any rate, whether the perfume meant anything or not, I was resolved not to miss.