It also seemed certain that the whole pit-prop business was a sham, a mere blind to cover those other operations from which the money came. But when Hilliard came to ask himself what those operations were, he found himself up against a more difficult proposition.

His original brandy smuggling idea recurred to him with renewed force, and as he pondered it he saw that there really was something to be said for it. Three distinct considerations were consistent with the theory.

There was first of all the size of the fraud. A theft of £4,000 to £6,000 or more a year implied as victim a large corporation. The sum would be too big a proportion of the income of a moderate-sized firm for the matter to remain undiscovered, and, other things being equal, the larger the corporation the more difficult to locate the leakage.

But what larger corporation was there than a nation, and what so easy to defraud as a government? And how could a government be more easily defrauded than by smuggling? Here again Hilliard recognized he was only theorizing; still the point had a certain weight.

The second consideration was also inconclusive. It was that all the people who, he had so far learned, were involved were engaged in transport operations. The ostensible trade also, the blind under which the thing was worked, was a transport trade. If brandy smuggling were in progress something of precisely this kind would have to be devised. In fact anything more suitable than the pit-prop business would be hard to discover.

The third point he had thought of before. If brandy were to be smuggled, no better locality could have been found for the venture than this country round about Bordeaux. As one of the staple products of the district, brandy could be obtained here, possibly more easily than anywhere else.

The converse argument was equally inconclusive. What hypothesis other than that of brandy smuggling could meet the facts? Hilliard could not think of any, but he recognized that his failure did not prove that none existed.

On the other hand, in spite of these considerations, he had to admit that he had seen nothing which in the slightest degree supported the theory, nor had he heard anything which could not equally well have referred to something else.

But whatever their objective, he felt sure that the members of the syndicate were desperate men. They were evidently too far committed to hesitate over fresh crime to keep their secret. If he wished to pursue his investigations, it was up to him to do so without arousing their suspicions.

As he pondered over the problem of how this was to be done he became more and more conscious of its difficulty. Such an inquiry to a trained detective could not be easy, but to him, an amateur at the game, it seemed well-nigh impossible. And particularly he found himself handicapped by the intimate terms with the Coburns on which he and Merriman found themselves. For instance, that very morning an excursion had been arranged to an old chateau near Bordeaux. How could he refuse to go? And if he went how could he watch the loading of the Girondin?