And, so saying, he stepped to the fore midship window of the pilot-house, laid his finger lightly upon the firing-button that controlled the discharge of the torpedo-shells from the tube in the extremity of the ship's sharp snout, and so placed his eye that he brought the jack-staff forward in a direct line with a very small notch in the window-frame. He stood thus, rigid and tense, while Sir Reginald did his part of the work; and presently he saw the jack-staff swinging slowly round toward the pirate cruiser. He waited thus until his two sights pointed something less than an eighth of a length ahead of the cruiser, and then he pressed the button hard. As he did so, something flashed like a sudden gleam of sunlight from the _Flying Fish's_ stem, a sheet of water some four or five yards in length leaped into the air from under the bows, and some six seconds later a blinding flash started out from the side of the cruiser, midway between her stem and her foremast. As the flash disappeared, Lethbridge, who was watching the ship through his binoculars, saw a great black patch on the cruiser's side, exactly where the flash had occurred; and while he was still wondering what it could mean he became aware that the craft was rapidly settling by the head. And before he could sufficiently recover from his astonishment to utter a word, the cruiser's bows sank to a level with the water, her stern rose high in the air, with the propeller still spinning round, and in another second she dived forward and disappeared, with the black flag still fluttering from her main truck. CHAPTER TWENTY THREE. A SHIP OF MYSTERY. "Gone!" gasped Lethbridge, as he turned round and stared with startled eyes at the other occupants of the pilot-house. "By George! Mildmay, that was a splendid shot of yours; caught her fair, and tore a gap in her side as big as a church-door! Those torpedo-shells of yours, Professor, must be truly frightful things, for a single one of them to be capable of destroying a ship like that in a moment. How big would she be, Mildmay?" "Oh, I don't know; something over four thousand tons, I should say-- hillo! what is the matter? Have we stopped?" exclaimed Mildmay, as the ship's way suddenly eased up almost with a jerk. "Yes," said Sir Reginald quietly, "I have stopped her until we can consider what is the proper thing to be done next. Are we to go on and speak that liner, or are we to let her go on her way without communicating?" "What has the liner herself to say about it?" asked Mildmay, picking up his glasses from the small table upon which he had laid them down, and bringing them to bear upon the steamer.