Perhaps ten minutes more and then Lord Hastings gave the command to heave to. For, through the periscope, less than a quarter of a mile away, he could make out the form of a giant German battle cruiser, a trifle to starboard. The electric signal board flashed its message of death: "No. 5 torpedo!" "Ready!" "Fire!" "Click!" Just this little sound and then Lord Hastings gave the command to rise, for he wished to witness the effect of the torpedo on the German cruiser. The D-16 rose swiftly, but not as swiftly as the torpedo had sped on its way. For when the submarine reached the surface the torpedo had already done its work, and the German cruiser was helpless. Men were jumping into the sea on all sides and swimming away. Jack was struck with a sudden idea. He turned to Lord Hastings. "If we could pick up one of those fellows," he said, pointing, "perhaps we could find out what has happened to Frank." "Good," replied Lord Hastings, "it shall be done." Upon his command the submarine forged ahead slowly directly toward the doomed German cruiser. Heads of men swimming began to bob up and down on both sides. Jack, leaning over the side, which was almost level with the water, suddenly stretched forth a hand and dragged a German petty officer aboard. Frightened almost out of his wits, for he had not perceived the dark outline of the submarine, the German struggled fiercely; but he was no match for Jack, who soon subdued him. The man was dragged below, and upon Jack's request, the submarine was again submerged. When the prisoner learned that he was aboard the British submarine he braced up, and when he found that he was not to be harmed, he proved willing to talk. "Where is the English prisoner whom you captured yesterday?" Lord Hastings asked him. "He has been sent ashore," was the reply. "He was to have been taken to Berlin today, to be held as a prisoner of war; but I understand that for some reason it was put off till tomorrow." "I see," said Lord Hastings, and as he did not wish to put the prisoner on his guard, he talked for some minutes of other matters. "By the way," he said finally, "how is our friend guarded? Is he locked in a cell, or what?" "Yes," was the reply. "He refused to give his parole, so naturally he had to be confined. However, he is perfectly comfortable and is being well cared for." "So he is locked up in the fort," said Lord Hastings. "Then there is no chance of his being so foolish as to attempt to escape." "It certainly would be foolish," said the prisoner, "although once outside the cell, he might lose himself for a while; but of course there would be no chance of his getting out of the country. You see, we are perfectly safe here, or were until you came along, so it is unnecessary to keep such a close watch." "And where is the fort where he is confined?" asked Lord Hastings. "Only a short distance from the edge of the canal. It is called Fort Kaiserin."