Both weapons were discharged simultaneously. The missiles rose with apparent slowness. Viewed from the bridge, they looked like enormous cricket-balls being lobbed by a titanic hand. Describing parabolic curves, they struck the water almost vertically--one on either side and about ten yards from the periscope. There was a double splash. The tip of the periscope was hidden in spray, but still there was no explosion. The depth-charges had to sink to a distance of thirty feet before they were automatically detonated. Right aft, the Gunner was standing knee-deep in water, with a hand over his eyes as he watched. In vain the Skipper shouted to him to take cover. His interest in what was about to take place had rendered him deaf to every other sound. Suddenly there was a stupendous upheaval. Almost the entire length of the submarine was lifted clear of the agitated sea, but only for a few brief moments. Completely torn asunder, the doomed craft disappeared from view, amidst a pall of smoke and under a rapidly increasing circle of oil and charred débris. A wave of foaming water swept over the now submerged stern of the decoy-ship, hurling the zealous Gunner Jones against the dummy steering wheel. The _Complex's_ stem rose sullenly, until the whole of her forefoot showed clear. She was making her last plunge. The concussion of the exploding depth-charges, while they had sent her foe to her doom, had also hastened her parting. "Abandon ship--all hands!" shouted the Old Man. CHAPTER XXI A Stern Chase It was the work of a few moments for the rest of the highly-disciplined crew to take to the boats that, regardless of the danger, had closed to rescue their comrades. Captain Meredith was the last to leave. True to the traditions of the British navy, he stood on the bridge until not another soul remained on board. Then, with the confidential code-book under his arm, he leapt nimbly into the stern-sheets of the cutter. A couple of cables' lengths from the doomed vessel, the crews of the various boats lay on their oars and awaited the end. There was almost dead silence. Although the men were elated at having scored heavily off their treacherous foes, the sight of their erstwhile floating home disappearing for ever from mortal eyes was a sad one. Now and then some of the wounded groaned involuntarily. Those whose hurts were light insisted upon sitting up and watching the awe-inspiring sight. The _Complex_ went quietly. There was very little commotion in the water, no rush of compressed air. With the White Ensign streaming proudly in the light breeze, she slipped slowly beneath the surface and disappeared from view. "The seaplanes, my hearties!" shouted a bull voice, and a horny hand was raised with the finger pointed at an angle of about forty-five. "Smart work, by Jove," commented Cavendish, glancing at his wristlet watch.