He was still considering what steps he could take to prevent the tale of his adventures being spread abroad, when something very black and solid arose out of the water only a few yards away. Although, considering the darkness, it was quite unnecessary, he crawled round to the other side of the buoy in order to take advantage of the "cover" afforded by the pillar supporting the bell, for he knew that black object must be the conning tower of a submarine rising to the surface. Then he heard voices, and at the same moment the chain attached to the tank began to slide over his boots, showing that the Germans were hauling it alongside their vessel. The moment for action had come. Drawing his revolver he fired it in the air, and before the report had died away the buoy and the submarine were lit up by the brilliant beam of the _Knat's_ searchlight. The Germans, of whom there were several on the _U_ boat's platform, made a simultaneous rush for the open hatch, for all the world like startled rabbits diving into their burrows. But before they disappeared inside a yellow flame flashed out from the vicinity of the searchlight, followed by a dull roar. Another and another followed in quick succession; the submarine suddenly tilted up, gave a lurch, and then disappeared for ever beneath the waters of the North Sea. * * * * * "Pity you plugged that petrol tank as well," remarked Lawless as he and Trent sat at breakfast in the _Knat's_ cabin. "We might have used it for bait quite a number of times." "Couldn't be helped under the circumstances. However, I suppose this'll mean promotion for you and paragraphs in the papers headed 'Naval Officer's Amazing Ruse. How a German submarine was sunk.'" "There's my official report," said the Lieutenant, handing the other a paper. Trent glanced through it and looked up with a puzzled expression. "You don't mention the bell-buoy," he said. "Trent, do you consider that, in a stand-up scrap, I could lick you?" The Sub-Lieutenant regarded Lawless in amazement. "Why," he answered at last, "I suppose you could. You're nearly double my weight, and you've got a longer reach." "Because," went on Lawless, "if you ever breathe a word about the way in which I collared that submarine I'll pound you so that your most devoted aunt won't recognise her dear sailor nephew." He rose from the table. "Sitting on a bell-buoy catching submarines with a bent pin! Why, it'd haunt me to my dying day," he murmured as he left the cabin. CHAPTER IX ABANDON SHIP! "Ah me!" sighed Lawless as he gazed at a small heap of documents which lay before him on the cabin table. "It's a weary world, my masters, and full of creditors." "What's the matter now?" asked Trent, glancing up from a letter he was reading.