The two peered long and earnestly at the German vessel, but not a sign of life could they make out. "Must all be dead," said Jack. "Or asleep," replied Lord Hastings. "And that's about what's the matter," agreed Jack. "What shall we do with the boat, sink her?" "I suppose so," replied Lord Hastings, "but I have another idea." "What is that, sir?" "Well, forcing a passage of the Kiel canal is bound to prove ticklish work. Now if we could lay our hands on the officer of that vessel, we might persuade him to pilot us through." "A good idea," said Jack, "if we could only get him." "We shall make a try at it," said his commander. "How?" asked Jack. For answer Lord Hastings turned and went below, and in another moment the D-16 began creeping toward the German submarine. At a distance of only a few yards she stopped and Lord Hastings motioned to Jack to follow him, as he dropped over the side into the little launch which had been lowered into the water. To Frank he called: "If we do not reappear on deck within ten minutes, sink her." Frank indicated that he understood, and Lord Hastings and Jack put off for the enemy. They clambered quietly aboard, and descended below without so much as being challenged. Just at the bottom of the companionway they came upon the figure of a man who emerged from one of the compartments. At sight of the British uniforms the man staggered back and his hand went to his side, but before he could draw a weapon, Jack had him covered with his own automatic and spoke quietly. "One move and you are a dead man," he said quietly. "Who are you?" asked the man in a low voice. "British officers," said Lord Hastings. "And you?" "Captain Bretog, commander of this vessel," came the reply. "Very good, captain," said Lord Hastings. "You are our prisoner, and I must ask you to step upon the bridge." "How did you get here?" asked the German in surprise. "In a little submarine of our own," said Lord Hastings with a smile. "Come, now, captain." The captain moved toward the companionway, but just as he was about to go through the door, he turned and struck out at Lord Hastings. The latter dodged the blow and leaped quickly back, at the same time drawing his revolver. "No more of that," he said sternly. "Now move." But at that instant a German sailor appeared in sight. Perceiving the British uniforms, he cried out in surprise. An instant more and there came the sound of tramping feet, and half a dozen men tumbled into sight after him. Lord Hastings put the German commander in front of him, and Jack stepped quickly to his commander's side, their four automatics covering the superior numbers of the enemy. "One move from any of you and you are all dead men," said Lord Hastings calmly. "We'll shoot you where you stand, and my vessel will blow you to atoms within half a minute." He turned to the German commander. "Captain," he said, "order these men on deck ahead of you."