Any one who could have seen that happy boy's face at the window of the second-class carriage, as the train steamed majestically out of the station, would scarcely have dreamed of the deep meaning concealed beneath that ingenuous smile. Smile on, Septimus, yet beware! The sleuth-hound is already on the track! Sub-Chapter III. THE SLEUTH-HOUND. Solomon Smellie, of Scotland Yard, had yet his way to make in the world. He was not exactly young, for time had already thinned the luxuriant growth of his hair, nor was he without encumbrance, for he had fifteen children. Yet he was an active and intelligent officer, and had once detected something--he forgot what. But that is not to the point. What brought him, walking on this particular evening, to the foot of the beetling cliffs? Ask the howling wind, which ever and anon flattened him against the chalk or drove him miles inland up some cavernous cave. Be that as it may, he walked. "I wish I could detect something in all this," said he, pulling himself together, and glancing scornfully into the darkness. As he did so, Captain Peeler's corpse alighted gracefully on the sand at his feet. "Ah, ha!" said he, "this looks like business. Now let me think. How comes this here?" There were no footsteps in the sand beside his own, therefore the miscreant or miscreants must have escaped in some other direction. "Aha!" said he, presently looking up. "They may be up there." And he leapt actively to the beetling summit. "Better and better," said he, looking round him and observing a hoof mark in the yielding clay, of which he promptly took a plaster cast. "Another link, ha, ha! the murderer was a horseman!" And he sat down and wrote a lucid report on the whole case for his sergeant. Solomon Smellie was in luck assuredly! Scarcely had he concluded his literary labour, when, at a distance, he perceived a twinkling light. "Ha, ha!" said he, "now see how the real artist in crime works. Yonder is a light. The murderer cannot have gone that way. Therefore he has gone this." And he stepped into the railway station just as Sep's train steamed out. "Too late, this time," muttered he, between his teeth. "But time will show--time will show!" Never did man speak a truer word! Sub-Chapter IV. THE STOWAWAYS. The "Harnessed Mule" was a splendid vessel of a hundred and fifty tons; and as she sailed past the Nore like a floating queen flapping her white wings in the breeze, she reminded the beholders that England still rules the waves. Her crew consisted of a skipper, four men, and a boy. Was that all? Who is this lurking figure in the forward hold, who, with a complacent smile on his lips, gazes on a crumpled map, and ever and anon sharpens a gimlet? There is a stowaway on board the "Harnessed Mule." One? There are two. For in the stern hold lurks another figure, also smiling, as the wind plays through the thin hair on the top of his head, and mutters to himself--