's Corporal Shrimp!" called Hal, springing up and running down
toward the shore. Noll followed his chum on the instant, both arriving
at once.

"Well, what do you rookies want here?" demanded Shrimp, turning upon
them with an oath.

"I guess we're here on duty," clicked Hal resolutely. "You're supposed
to be in arrest, Corporal, and here you are leaving the post on the
sly!"

"I'm out of arrest, and on duty. Stand aside!" snarled Shrimp, his look
becoming very ugly.

"Is it a kind of duty that calls for you to sneak away in this fashion,
put on citizen's clothes, and sink your uniform in the bay?" demanded
Private Overton mockingly. "If you tell me that, Corporal, I don't
believe you."

Corporal Shrimp uttered another ugly oath. Then, with a flashing
movement, he drew a service revolver from under his blouse and thrust
the muzzle almost in Private Overton's face.

CHAPTER VII

WHEN THE GUARD CAME

"LOOK out, Sim Shrimp!" called the boatman quickly, warningly.

For, while Hal had stood looking gamely at the revolver, Noll Terry had
side-stepped, and now leaped at the corporal.

Whack! Noll struck up the glinting barrel of the weapon.

Private Overton, seeming to move in the same instant, leaped forward in
front.

Bang! The revolver was discharged, but harmlessly into the air, as both
rookies tackled the corporal and bore him to the ground.

"Help, here, Bill!" cried Shrimp, as he found himself going over
backward.

The boatman leaned over to snatch up an oar. As he rose with it he saw
Private Hal Overton rise with the corporal's revolver in his hand.

"Stay where you are, Corporal, and don't make any fuss," advised Hal
grimly. "Your friend had better stay where he is if he doesn't want to
know what it feels like to have a bullet going through him."

"Drop that gun, and let me up! Get out of my way," ordered Shrimp.
"You're interfering with me in the discharge of my duty, and I'll put
you both in a lot of trouble."

"Don't you try to get up," ordered Noll, who had thrown himself across
the corporal and was holding him down.

"Sentry!" yelled Hal. "Sentry."

He should have called, "Corporal of the guard!" but he didn't know that.

Another shot at some distance was heard, followed by a lusty shout from
a sentry of:

"Corporal of the guard, post number seven!"

"Let me up out of this, and I'll let you both off," proposed Corporal
Simeon Shrimp.

"You'll stay just where you are," ordere