The time passed slowly, but darkness came at last; and with its coming Lord Hastings emerged from his cabin, attired in the uniform of a German lieutenant-commander. "I forgot to tell you lads to don your German uniforms," he said. "I'll wait now, but make haste." Frank and Jack hurried away in response to this command and soon were attired in the full regalia of German lieutenants. Lord Hastings eyed them approvingly. "There is no use talking," he said, "I have always thought it--and I am sure of it now--both of you would make first-class Germans. You may give the command to come to the surface, Mr. Templeton." A few moments later the D-17 rode gently upon the calm sea within the fortifications of Heligoland, the greatest German military fortresses, and considered among the strongest and most impregnable in the world. It was very dark and the night was perfectly still when the three forms ascended the ladder and emerged from the conning tower to the bridge--open now that the submarine was above water. A fourth figure followed them, that of Price, an aged British tar, whom Lord Hastings had designated to take command in their absence. "Don't forget now, Price," said Lord Hastings sternly, "you will submerge immediately we have put off and on no account will you come to the surface again until 9 o'clock to-morrow night. Then you will rise in exactly this spot--and be sure that you are on time. Do I make myself clear?" "Perfectly, sir," replied Price, saluting. "Good. Then launch the boat." This was done immediately and a few moments later Lord Hastings, Jack and Frank were proceeding rapidly shoreward, the engine of the small motor-boat muffled so that all that could be heard was the faint sound of the exhaust. In the darkness, as they sped on, loomed great, dark shapes--the forms of some of the most powerful of the Kaiser's formidable sea fighters. Smoke poured from their funnels and faint lights glowed aboard. "Ready for action at any moment," said Lord Hastings. "So they are," agreed Frank. "Great Scott! It doesn't seem possible that so many of these great craft could be afraid to venture forth to give battle." "No, it doesn't," declared Jack. "But at the same time, you must remember there are more and still more formidable craft waiting for them to come out and try it." "That's true, too," admitted Frank. "I wish they would try it, though. I don't believe many of them would get back." "Evidently the Germans have the same belief--which is the reason they haven't tried it," said Lord Hastings, smiling in the darkness. "Silence, now," he cautioned them, after a moment. "We are close to the shore. Let all further talk be in German." Five minutes later the motor-boat came to a long pier, which extended far into the water.