Owen fired two more shots from his dangerous automatic
revolver as Hal caught at the rail of the boat.

"The last chance to save us!" repeated Jack.

"I know it," came, breathlessly, as the dripping Hal dropped down
the manhole. He did not even wait to make use of the stairs.

By a fortunate impulse Grace Desmond fell back as young Hastings appeared.
Hal's right hand shot out, gripping the wrench. The "Pollard" gave
a surge that all aboard believed to be her final one.

Yet Hal hung to his post, resolved to go down trying.

There was a hiss of compressed air. The "Pollard" didn't quite make
the death plunge. Then she seemed to go, ever so little, toward a
more level keel.

"I--believe--I've got her!" cried Hal Hastings.

A moment or two later he felt sure of it. He gave a cheer to ease
his pent-up feelings, then suddenly gasped:

"Jack, do you know how much compressed air there is?"

"No," replied Benson, blankly.

"Heaven grant there's enough for what we must do," prayed Hal, aloud.

There were two shots over in the yard just now. The three young people
heard the discharges, though they paid no heed to them at this critical
instant.

Slowly the "Pollard" continued to regain evenness of keel.

Then Hastings, shifting the wrench to another part of the compressed
air apparatus, opened the sea-valves of the amidships water tanks
to expel water.

Briefly, now, they knew that the "Pollard" had risen. Also, she was
resting on an even keel. Hal, bedewed with cold perspiration, darted
up the stairs to the conning tower. He looked out, and the first
glance told him the "Pollard" was riding the water as she should.

"It's all right--now," he called down, with a strong effort at calmness.
"Jack, what on earth happened that you had to call for help!"

Then he caught sight of his chum, lashed to the stanchion. Hastings's
mouth went wide agape with astonishment.

"Jack--how on earth--did Josh Owen--"

"Yes," nodded Benson, quickly. "This was his work. Get me free from
this stanchion, won't you?"

Despite his elaborate effort at calmness Hal Hastings shook so that it
was some seconds before he could get his knife from a pocket.

"Wait till I steady down," Hal muttered, grimly. "I'm afraid of stabbing
you."

At last, however, Hastings controlled his right hand enough to feel
safe in slashing the cords. Jack, weak-kneed, stepped away from the
stanchion, though he was still handcuffed.

"Thanks,