A sound above told the submarine boy the worst. The water was gently rippling against the edges of the platform deck. That told him, all to plainly, how near the diving boat was to doing the work for which it had been built.

Could Jack have been close enough to see just why Grace was failing in her effort he might have told her better just what to try to do. Now, he tried to explain, rapidly. The fault was not with her strength; there was an exact knack needed in the use of the wrench.

On shore, in the yard, Josh Owen crouched low in his place of concealment. He had failed to prevent Grace from starting in the rowboat because, until it was too late, he did not believe the plucky young woman had any such intention.

"It's too bad for the gal to go to the bottom, too," half sighed the raging one. "But she shouldn't meddle."

Hal came swinging along down the street, having left Eph Somers behind in the village. Through the yard came young Hastings, whistling. By instinct he turned to look at the boat, and what he saw made him gasp, then leap forward in the start of a sprint.

Straight down to the harbor's edge he raced. Then, seeing the rowboat adrift, Hal, after one more look at the sinking submarine, leaped into the water without stopping even to shed jacket or cap.

Splash! In the same instant that he sprang, Josh Owen jumped up.

"Come back here, or ye'll wish ye had!" raged the ex-foreman.

Hal Hastings heard, though he did not even take the trouble to answer, but struck out frenziedly, for his chum's calls for help now rang in his ears.

There was the sound of a discharge, a sharp split of fire from a weapon that Owen held in his hand. A bullet struck the water just before Hal's nose, dashing the spray back in his face.