t about which you're in doubt."

"We ought to run that rascal down, sir," answered Jack Benson, rising.
"Unless--"

"Unless what, Benson?"

"Why, sir, unless he's more clever than a rascal usually succeeds in
being. I haven't lived so very long, Major Woodruff, but, from what
little I've seen of the world, it has struck me that the cleverest
scoundrels are always just a little less smart, in the end, than the
average of honest men."

"I hope you'll prove it, in this case," replied the major. "And now, to
signal your boat. We'll run both craft in at the ordnance dock at Fort
Craven."

A couple of miles away Eph Somers was slowly running the submarine back
and forth over the water in seeming aimlessness. In response to sharp
blasts from the whistle of the Army tug, the "Spitfire" was seen to
turn and head for the tug.

"Mr. Somers, you will follow in our wake," shouted Major Woodruff, when
the two craft were within hailing distance of each other. "We will
show you where to make fast at the ordnance dock."

"Very good, sir," Eph responded, with a salute.

A little later in the forenoon both boats docked at the water front of
Fort Craven.

"You'll come up to my quarters, now, and meet Lieutenant Ridder,"
announced the Major, when he had gathered the submarine boys together,
and when Jack had given necessary explanations to Williamson.

"You may not see us again, for a few days," Jack informed the machinist,
in winding up.

"That won't surprise me so very much, either," laughed the machinist.
"Things are always happening, where you are, and mysteries have ceased
to puzzle me."

"Have you young men ever been on a military post before?" inquired
Major Woodruff, as he led them up from the dock.

"Never sir," replied Jack. "We have seen considerable of Navy life, but
this is the first time we've ever been at a fort."

"You don't see much about this place, do you," laughed the engineer
officer, "that makes you think of a fort?"

"Not much," Benson admitted.

"Yet we have a fighting plant here that could prevent a big fleet,
indeed, from getting far up the bay at the important cities beyond.
That is," Woodruff continued, thoughtfully, in a low voice, "if the
enemy, in advance of his coming here, doesn't know all about our defenses
through the work of spies."

Just at the point near the dock, Fort Craven looked not unlike the yard
of a big factory plant. Wagons going and coming constantly heightened
t