Von Schellen, his hand on the wheel of the periscope mechanism, awaited a nod from his chief. Receiving it, the younger officer turned the wheel, sending the periscope up a foot above water. On the white surface of the shaded table beneath Dave saw the image of a vessel. "The fellow yonder has not yet sighted us," said the ober-lieutenant, grimly. "We are about to send him a torpedo. Yonder craft is to be our game--Yankee steel and Yankee meat!" As for Dave, as he stared in horror at the image on the table he recognized in the ship mirrored there Dan Dalzell's own command, the "Reed." Forcing himself to speak calmly, and to act a part Dave begged: "One moment longer, please! Let me see whether I can recognize the doomed craft." "Doomed, indeed," chuckled the ober-lieutenant. "We are in position and I am about to fire. Be ready to drop the 'scope, von Schellen!" But Dave Darrin, knocking von Schellen's hand away, seized the lever, forcing the periscope to rise to its full height above the conning tower. Nor did he stop there. With the mightiest twist and wrench of which he was capable he jammed the lever so that it could not be promptly operated to lower the periscope. "Stop!" thundered von Schellen, leaping to his feet, his face purple with rage. "I've stopped," assented Darry, smilingly, as he stepped back. "Do you realize what you have done, scoundrelly Yankee?" hissed the ober-lieutenant, also rising and drawing his revolver. "Of course I do," Dave smilingly assented. "You have jammed the periscope. But at least we can dive when we need, for--there!" With deft manipulation of a small device the German commander added: "I have closed the valves of the 'scope, which will now admit no water if we dive. You did not succeed, Herr Darrin. But you will draw upon us the Yankee fire if yonder commander is now able to sight our scope." As if to verify the statement a muffled sound came to them through the water. Glancing down swiftly at the table von Schellen saw that reflected which caused him to exclaim: "The Yankee destroyer has opened upon us with her forward port gun. And there goes the starboard gun!" Von Schellen, at a nod from his chief, signalled the orders for diving. The ober-lieutenant saw the "Reed," as pictured on the white table, come steaming toward the submarine at full speed. "You idiot!" raged the German commander. "Your treachery has betrayed us, and now the Yankee will do his best to sink us and drown all on board here." "That's what I'm praying right now he'll do!" cried Dave Darrin, his face radiant with the glory of the thought. CHAPTER XI A VICTIM OF COURTESY "AND what about the woman we have on board?" demanded the ober-lieutenant, hurriedly. "Would you destroy her, too--cause her, if you could, to die the death of drowning helplessly?" "I--I had forgotten her," Dave confessed. But from the passageway came a prompt response.