"Attention!"

The officer in command of the torpedoes had his hand on the lever which would release the first deadly projectile already in the tube. The sailors made ready to launch the second as soon as the first was gone.

Several seconds passed. Frank and Jack stood in deathlike stillness. Both realized the tragedy that was about to be enacted, and both were aware of their powerlessness to avert it.

Into the minds of both flashed a thought of springing upon their captors, but each, after a moment's reflection, realized the futility of such an action. It would merely delay the firing of the first torpedo.

And so they stood while the seconds passed, the heart of each in his throat. Suddenly the first sign on the board disappeared. A moment later and a second command appeared. Frank and Jack read it simultaneously, and both started forward with a cry.

The word that now stared them in the face, in red, glowing letters, was:

"Fire!"

With a single jerk, the officer released the first torpedo, even as both lads, unable to endure the suspense and inaction any longer, leaped upon him. There was a short, metallic click, the noise of water rushing into the empty tube, and it was over. The first torpedo had sped on its errand of destruction and death.

The German officer turned just in time to grapple with Jack, who was now upon him.

"Seize them, men!" he cried, and struck out sharply at the lad. But Jack was too quick for him, and his right fist went crashing into the German's face. Frank was with him now, and the two turned to face the onrushing sailors.