“Get down to the engine-room, you there,” the millionaire continued. “Drop your barker first; that’s better. Now slope, an’ let’s have no tricks, or you’ll get hurt.” Like a beaten hound, the fellow slunk below, never attempting to possess himself of the dead footman’s revolver, which lay beside the corpse. The American was master of the situation. * * * * * As the sound of the plotters’ footsteps died away, Oswyn flung open the window of the dining-room and rushed in. One moment he fumbled for the switch, the next, a dazzling flood of light poured into the room. Before the three bound men had recovered from their surprise at his unexpected appearance, Oswyn had cut their bonds and removed the gags. “Where have you sprung from, Frank?” cried the inventor, stamping about the room in his efforts to restore the circulation to his numbed limbs. Briefly the doctor told him of his fortunate meeting with Haverly at Carnmoor, and the succeeding events. As he finished speaking, Seymour left the room, returning in a moment with a brace of revolvers. “Come,” he cried, “we may yet be in time to take a hand in the game.” Out into the night the four men plunged, and raced down to the dockyard; but they were a few moments too late. The submarine had gone. The shock of this discovery stunned them for a time. They had counted on Haverly keeping the scoundrels from boarding the vessel; but it seemed clear to them that their American friend had failed in his undertaking, and had paid the penalty of his daring. “Silas must have got wiped out,” Oswyn muttered sadly; “he would never have let them get possession of her otherwise,” in which statement, as the reader knows, Frank was mistaken. “What’s the next move?” Seymour asked. “Your craft’s too swift to think of pursuit, I suppose?” “It’s hopeless to think of recovering her,” returned the inventor. “What’s that?” A brilliant light had flashed over the dark waters of the bay. “There she is!” Mervyn cried, and an instant later the torpedo-shaped craft became visible to each of the watchers. But her movements puzzled them; she appeared to be making for the dock entrance. Slowly she crept forward, seeming to feel her way as she advanced, until the four standing on the quay could make out the three forms in her turret. Then comprehension burst upon them! “Good old Silas!” cried Seymour; “he’s got the drop on our bold conspirators this time.” Garth laughed boisterously in his rapture at the recovery of his invention. Through the dock gates the vessel crept to her old mooring-place. Almost ere the engines had ceased to throb, the four had leapt aboard, and were crowding into the turret. Within a few moments the two uninjured rascals and their wounded chief were securely trussed, and locked away in one of the workshops, there to await removal to the local jail.