The boat was well built, and the commander had perfect confidence in her. This was not his first experience of the kind. Exactly a year before, he had been out in the Cattegat in an E-boat and had met ‘a wrong un’--a _Greif_ or _Möwe_, which had opened fire on him with four 6-inch guns at 2000 yards and straddled him at once. The boat had to dive as she was, in complete surface trim. Shot after shot fell close to her; she was shaken by explosives and struck by splinters. Finally a 6-inch shell came alongside and threw up a huge column of water which fell plump on the commander as he descended through the hatch. Part of it accompanied him down the ladder, but he had the presence of mind to draw the lid down behind him, and he and his boat lived to tell the tale. So he knew that a British submarine can stand a shock or two. But what made him really anxious was the question--which he hoped would occur to no one else on board--why did those two depth-charges fall so near one another: why did the enemy drop the second so close to the first? The horrible suspicion came into his mind that his position was being given away by something that he could only guess at--some noise or some escape of air bubbles or oil which was reaching the surface. [Illustration: ‘A huge column of water which fell plump on the commander.’] What was to be done? Nothing, but to lie closer than ever, and enjoy the calm of the man who has done all that is possible. The order was given to stop all motors, even the Sperry motor for running the gyro compass. All vent valves, and other possible leaking places, were inspected and reported tight. Then came the third explosion, the most violent of all. Lights went out suddenly, and the crew--groping in darkness--thought that the end had come. For a moment the ship seemed to be stunned; then the lights reappeared. They had not been injured, but the shock had thrown all the chopper-switches on the auxiliary switchboard to the ‘Off’ position. Not a trace of a leak could be discovered--the ship was alive still, and without a mortal wound. In her commander’s judgment it would take a direct hit, or something very near it, to kill her.