Alone in one of the first-class carriages was a passenger who had accepted the situation with the most matter-of-fact indifference from first to last. He had made his arrangements for the night, with the skill and deliberation of an experienced traveller; and as the morning advanced he had composed himself, as comfortably as circumstances permitted, in a corner of his carriage, now and then casting a keen, comprehensive glance at the country through which he was being carried. These glances, however, were evidently instinctive and almost unconscious. For the most part he gazed straight before him with a preoccupied frown and a grave and anxious expression in marked contrast with his physical imperturbability. He was a man of apparently three or four-and-thirty; tall; rather lean than thin; and very muscular-looking. His face, and the right hand from which he had pulled off the glove, were bronzed a deep red-brown, and he wore a long brown beard; but he was not otherwise remarkable-looking. His eyes, indeed, were very keen and steady, but the rest of his face conveyed the impression that he owed these characteristics rather to trained habits of material observation than to general intellectual depths; the mouth was firm and strong, but neither sensitive nor sympathetic, and the straight, well-cut nose was as distinctly too thin as the rather high forehead was too narrow. On a much-worn travelling-bag on the seat beside him, was the name Dennis Falconer. The train steamed slowly into the station at Nice at last; the traveller stepped out on to the platform, and the shade of grave preoccupation which had touched him seemed to descend on him more heavily and all-absorbingly as he did so. He was walking down the platform, looking neither to the right nor the left, when he was stopped by a quick exclamation from a little wiry man with a shrewd, clever face who had just come into the station. “Falconer, as I’m alive,” he cried. “Well met, my boy!” The gravity of the younger man’s face relaxed for the moment into a smile of well-pleased astonishment. “Dr. Aston!” he exclaimed. “Why, I was thinking of looking you up in London! I’d no idea you were abroad!” The other man laughed, a very pleasant, jovial laugh. “I’m taking a holiday,” he said. “I don’t know that I’ve any particular right to it! But I don’t know these places, and I took it into my head that I should like to have a look at a carnival in Nice. And you, my boy? Just back from Africa, you are, I know. You’ve come for the carnival by way of a change, eh?” Falconer’s face altered. “No!” he said gravely, and with a good deal of restraint. “I’ve not come for pleasure. Very much the reverse, I’m sorry to say.” He paused, apparently intending to say no more on the subject. But the keen, kindly interest in his hearer’s face, or something magnetic about the man, influenced him in spite of himself.