Ordering the boat's crew to stand by, Wakefield went below once more. By the aid of an electric torch, for the internal lighting arrangements had given out, he found the levers that operated the big valves. So great was the inrush of water that Wakefield fancied he would be trapped by the miniature Niagara. Without waiting to manipulate the second sea-cock, he hastened precipitately on deck and followed Meredith into the dinghy. "Done the trick?" inquired Morpeth, as the two R.N.V.R. officers regained the mystery ship. "She doesn't seem in a hurry." Nor was she. It seemed quite a long time before the volume of water admitted into the U-boat's hull made any visible change in her trim. At length her freeboard diminished. She began to settle by the stern. "I suppose you made certain that there were no other prisoners of war on board?" inquired Captain Cumberleigh. "Trust me for that," replied Wakefield. "Why did you ask?" "Because I'm rather mystified about a fellow who called himself Captain Fennelburt. He was with us when von Preugfeld collared us. One of the mutineers pitched me a yarn to the effect that von Preugfeld set him ashore. If so, what was the motive?" "I'll see Morpeth about it," decided Wakefield. "Ask von Preugfeld," suggested the skipper. "I can't do so myself just at present. Make him own up, and don't stand any nonsense." Cumberleigh, Wakefield and Blenkinson went below to interview the prisoner. They acted on Morpeth's tip and stood on no ceremony. Time was a consideration, as the U-boat was sinking and they wanted to see the end. Wakefield came straight to the point. "I understand, Kapitan von Preugfeld," he said sternly, "that you had on board another prisoner, a Captain Fennelburt of the R.A.F. He was not found when we searched U 247. Now where is he?" "You ask him," replied von Preugfeld, indicating von Loringhoven. "I do not know," protested the unter-leutnant, "but he does." Evidently von Loringhoven was getting pretty sick of being made a convenience of by his egotistical skipper. Wakefield's brows lowered. There was an ominous glint in his eye. "I give you five seconds," he said darkly. "Otherwise, if you refuse to tell me, back you go on board U 247. I might add that she is sinking. Now: one... two... three... four---" "I tell you!" exclaimed von Preugfeld. "All I tell you. Der offizier he try to escape. He vos shot. It is der rules of der war." "Unfortunately for the statement," interposed Captain Cumberleigh, "I heard from one of your men that you landed him early this morning." "In dat case," rejoined von Preugfeld, shrugging his shoulders, "why you ask me? You take der word of a common sailor instead of a Prussian offizier--a von Preugfeld? I tell you he lie." Wakefield turned his back upon the bullying Prussian. "It's evident that there was no other British officer on board," he remarked to his companions. "We'll go into the matter later. Come along, if we are to see the last of U 247."