The other three men forthwith stepped to the nearest port that would afford a view of the chase, and gazed eagerly ahead. And there, immediately over the long, tapering, conical-pointed bow of the _Flying Fish_ they beheld, some ten miles distant, a small, faintly denned grey blotch on the mirror-like surface of the sea, with a trail of black smoke issuing from it, as though the furnaces on board her had just been freshly stoked. "We will descend and take to the water at once," remarked Mildmay. "The conditions could not possibly be more favourable for the success of our plans; and I take it that we shall all be glad to get this business over as soon as possible, and our suspense brought to an end." Therewith he laid his hand upon a small wheel, and gave it two or three turns, thus partially opening the main air-valve and admitting a thin stream of air into the vacuum chambers of the _Flying Fish_, with the result that the huge craft at once began to settle down toward the surface of the sea, upon which, a few minutes later, she floated buoyantly as a soap-bubble. Then the main air-pumps were set to work, forcing compressed air into the vacuum chambers, and causing the ship to sink very gradually in the water, while at the same time, to facilitate the operation of sinking, water was admitted into certain of the ballast chambers in the ship's bottom until she floated at her ordinary trim for cruising on the surface of the sea--that is to say, with the whole of her immense propeller completely submerged, and her conical-pointed bow buried to the depth of a foot or so. During this operation of submergence the engines had been stopped, but they were now sent ahead again at full speed; and some ten minutes later the singular-looking craft ranged up on the weather quarter of a big black-hulled steamer of about three thousand tons register, the round stern of which bore the name of _Ludwig Gadd_ in large, yellow-painted Russian characters. This alone was sufficient to identify her beyond question as the convict-ship of which they were in search; but if further evidence had been needed it was to be found in the "pen"--a stout, substantially built wooden structure of closely set palings, about ten feet high, that occupied nearly the whole of the fore-deck, except a narrow alley-way on each side of it to allow of the passage of the crew fore and aft, and which included the great main hatchway, the covers of which had been replaced by a stout grating, with a small aperture in it just large enough for a man to squeeze through, and at which a soldier with a loaded rifle stood guard.