He was perfectly correct. Two days later, as it turned out, Charles received a "confidential" letter from Paris, purporting to come from the head of a second-rate financial house with which he had had dealings over the Craig-Ellachie Amalgamation--by this time, I ought to have said, an accomplished union. It was a letter of small importance in itself--a mere matter of detail; but it paved the way, so Medhurst thought, to some later development of more serious character. Here once more the man's singular foresight was justified. For, in another week, we received a second communication, containing other proposals of a delicate financial character, which would have involved the transference of some two thousand pounds to the head of the Parisian firm at an address given. Both these letters Medhurst cleverly compared with those written to Charles before, in the names of Colonel Clay and of Graf von Lebenstein. At first sight, it is true, the differences between the two seemed quite enormous: the Paris hand was broad and black, large and bold; while the earlier manuscript was small, neat, thin, and gentlemanly. Still, when Medhurst pointed out to us certain persistent twists in the formation of his capitals, and certain curious peculiarities in the relative length of his t's, his l's, his b's, and his h's, we could see for ourselves he was right; both were the work of one hand, writing in the one case with a sharp-pointed nib, very small, and in the other with a quill, very large and freely. This discovery was _most_ important. We stood now within measurable distance of catching Colonel Clay, and bringing forgery and fraud home to him without hope of evasion. To make all sure, however, Medhurst communicated with the Paris police, and showed us their answers. Meanwhile, Charles continued to write to the head of the firm, who had given a private address in the Rue Jean Jacques, alleging, I must say, a most clever reason why the negotiations at this stage should be confidentially conducted. But one never expected from Colonel Clay anything less than consummate cleverness. In the end, it was arranged that we three were to go over to Paris together, that Medhurst was to undertake, under the guise of being Sir Charles, to pay the two thousand pounds to the pretended financier, and that Charles and I, waiting with the police outside the door, should, at a given signal, rush in with our forces and secure the criminal.