leaped back so that he upset and extinguished
his dark lantern.

"Wha-wha-what was that?" he faltered.

In the intense darkness that followed the flash Jack and Hal stole away.

Suffering all the terrors of a guilty conscience, increased by the
terror of the inky darkness under such circumstances, Josh Owen tremblingly
felt for his momentarily useless lantern. It took him some moments
to find it. Even then his fingers shook so convulsively that it needed
several trials before he got the light going.

By this time Jack and Hal were safely outside. More than that, Jack
held in his hand the padlock of the door, with the false key in it.

"Why not slam the padlock shut over the door and lock him in there
until we can get someone here?" whispered Hal Hastings.

By this time the two boys were hiding behind the corner of a nearby
building.

"I thought of that," whispered Jack, "and I'd like to do it. But Owen
has a fearful temper. If we locked him in there, and he knew he had
to be caught, he'd do thousands of dollars' worth of damage. As it is,
if you watch out, you'll soon see him quitting that shed and getting
away as fast as he can."

Not more than a few seconds later Josh Owen appeared at the door of the
shed. He shut off the light from his dark lantern, then stole swiftly
towards the fence. Going up and over, he vanished from sight.

"Now, we'll lock the shed, take this false key to Mr. Andrews, and let
him decide whether to rouse Mr. Pollard or Mr. Farnum," announced
Jack Benson.

Grant Andrews, as soon as he was aroused at the boarding house, and had
been made to understand, took the false key, saying:

"I'll go over to the hotel and call Dave Pollard. Then I'll do whatever
he says."

The inventor was greatly excited over the news borne to him by the
new foreman. Together they hurried to the Farnum yard, unlocked the
door to the submarine's shed, entered and made a hasty examination.

Thanks to the promptness of Jack Benson and Hal Hastings, Josh Owen
had not had time to inflict more damage to the forward sea-valve than
could be readily repaired.

"I guess that was what the infernal rascal meant when he told Jack
Benson that the 'Pollard' would dive to the bottom and stay there,"
exclaimed the inventor, in a shaking voice. He smiled a ghastly smile.

"We'll put a stop to such pranks after this," replied the new foreman.
"Until your craft is launched, sir, I'll sleep here nights, beginning