That officer moved restlessly about the Submarine, glancing from dial to dial and from one gauge to another; for a few minutes he stopped to talk to the torpedo-man standing by the closed tube. Finally he returned to his Captain's elbow, moistening his marred lip with the tip of his tongue; his face wore an unhealthy pallor and glistened in the glow of the electric lights.

"Is it an English ship, Herr Kapitan?" he asked again in his high, unnatural voice.

"Yes," snapped von Sperrgebiet. "Why?"

"I have a request to make," replied the Second-in-Command. "A favour, Herr Kapitan. It concerns a promise"—he lowered his voice till it was barely audible above the noise of the machinery—"to my betrothed."

For the first time von Sperrgebiet turned his face from the rubber eye-piece and regarded the youth with a little mocking smile that showed only a sharp dog-tooth.

"Don't say you promised to introduce her to me, Ludwig!" he sneered.

"No, no," said the other hastily. "But she made me promise not to return to her unless I had sunk with my own hands a merchant ship flying the cursed English flag."

"She is easily pleased, your betrothed," retorted the Oberleutnant, and moved back from the periscope. "Your request is granted. But remember I shall demand an introduction when we return…. It is a long shot. Fire when the foremast comes on, and do not show the periscope more than a few seconds at a time. I will give the orders after you have fired."

The Second-in-Command took up his position in the spot vacated by the Oberleutnant. His tongue worked ceaselessly about his lips and his hand trembled on the elevating wheel.

"There is smoke astern," he said presently. And a moment later. "The approaching ship looks like a liner, Herr Kapitan!"