Putting forth his whole strength, he commenced to turn the handle, thus opening the gates of the dock, and making a free passage for the submarine to the North Sea. The plotters had chosen their time well, for the tide was at its flood. Casting off the mooring ropes, the footman leapt aboard, and passed down the steps to the engine-room. Three minutes later the submarine crept out into the bay upon which the dock gave. The object of the conspirators’ plotting had been attained; the scheme was a gigantic success. The three scoundrels were not a little pleased with themselves as the boat glided swiftly across the bay under the guidance of the leader. They jested and laughed, flavouring their conversation with many an oath, as they pictured to their own delight the mortification of the inventor, whose craft they had stolen. Their mirth would perhaps have been less hilarious had they noted the grim figure creeping along the corridor below, towards the foot of the steps. “Jesting apart,” said the leader at length, “it’s a marvellous vessel. With this craft, armed in an up-to-date manner, we shall have the shipping of the entire world at our mercy. Not a warship on the seas will be able to resist us.” “For which we have to thank our estimable friend, the inventor,” returned one of his companions with a grin. At that moment there came a flash, twice repeated, from the darkness far ahead. “The _Night Hawk!_” cried the leader; “it is----” “Checkmate, gentlemen,” drawled a quiet voice behind them. At the words the three turned, to look into the gleaming barrel of Haverly’s revolver. “Hands up, you scoundrels!” he cried. “Ah! would you?” This last to the leader, who, with a savage oath, had made a grab for his breast pocket. A vicious spurt of flame leapt from the millionaire’s weapon, and as the report rang through the turret, the fellow fell back with a shattered wrist. “Out west,” snapped the Yankee, “when I say put ’em up, they generally calculate to put ’em up at once! I shouldn’t advise you to play tricks; this gun’s kinder impatient, and might go off again. Say, sonny! Just grab them spokes, and turn her round for the dock.” The scoundrel addressed moved trembling to the wheel, and, under the watchful eye of the American, brought the submarine round. “That’s the style,” Haverly said, “keep her there. I reckon you’re in for a warm time when Mr. Hilton gets hold of you. You should never attempt to run a picnic of this sort; it needs brains, gentlemen, and----” What Silas would have said further will never be known, for he broke off suddenly and ducked, just in time to escape a bullet from the revolver of the footman, who, aroused by the Yankee’s shot, had crept from the engine-room. Quick as thought Haverly’s weapon answered, and the footman, with a neat little hole in the centre of his forehead, dropped like a log. “Any more comin’ along?” Silas asked coolly; but the scoundrels had no heart left for resistance.