, "whether we can do any better
guessing than the Secret Service men as to the fellows who were kind
enough to lay that mine under us last night."

"Got it figured out?" asked the machinist, as he transferred, a generous
helping of bacon, eggs and fried potatoes, to his plate.

"For myself," put in Hal, "I'd suspect that fellow Gaston, in an instant,
if he had only been at liberty. That fellow has an eye that looks like
all the letters in the word 'r-e-v-e-n-g-e.'"

"That's so," nodded Jack, thoughtfully, as he ate. "But we happen to
know that Gaston is very safe under lock and key. By the way, fellows,
I don't suppose Mr. Farnum and Mr. Pollard have heard the news yet, or
they'd be out here on the double quick."

After breakfast Jack went ashore alone, to carry the exciting news to
his employers. He found Messrs. Farnum and Pollard in the breakfast
room at the Clayton. Both were astounded when they heard the news of
the night's doings.

"Who on earth could have put up such a job against the submarine?"
gasped David Pollard.

"I don't know, sir," Captain Jack replied. "But I've left Hal on
board, in command, and I mean to find out something about this business,
if there is any way to do it."

With that he excused himself, rising and leaving the table at which his
employers were seated.

Jacob Farnum gazed after his young submarine captain, then whispered to
the inventor:

"That youngster has some notion in his head of where to look for the
infernal criminals. And, ten to one, his idea is a good one that will
bear fruit!"

CHAPTER XX

A BRIGHT LOOK AND A DEADLY WARNING

Jack's employer gave him rather too much credit in supposing that the
boy had already worked out the problem of finding those who had made
the attack on the "Benson."

As the submarine boy left the breakfast room he felt as much in the dark
as ever. The only known spies who were still at large, for some reason
known only to the Secret Service men, were M. Lemaire, Mlle. Nadiboff
and Kamanako.

"This is rather earlier than either of that pair in the habit of showing
themselves," muttered Benson, as the first two names crossed his
thoughts. "I wonder whether I could get the least bit of an inkling by
going to the jail and talking with Gaston? If I could bluff him into
telling me anything, it might be so much gained. I might catch him off
his guard, if I could get him angry enough."

Full of this interesting idea, the