poral Sanders on receiving this order. "Right
shoulder arms! By twos, left march!"

Three minutes later the man on post three had been relieved, Hal having
been dropped into his place.

It was just after two o'clock in the morning when Private Hal Overton
began to pace his post, watching the relief vanish in the darkness in
the direction of post number four.

Then he heard a sentry's hail:

"Halt! Who goes there?"

"The relief."

"Advance, relief."

After that, the steps of the marching party died off in the distance.

In the darkest part of the moonless night Hal walked up and down before
the officers' quarters.

But he did more than walk. Making his own steps as noiseless as possible
Hal felt that he was truly "all ears and eyes."

Thus some twenty minutes went by.

Then, suddenly, just as Hal had passed the north side of Captain
Ruggles' quarters the young sentry halted like a flash.

Under the dim starlight he saw two shadowy forms leave by the captain's
back door.

Each carried a bundle, though Hal could not make out the size or shape
of either very distinctly.

"The burglars--at their tricks!" flashed Hal exultantly.

But he wasted no time thinking. In a twinkling he slipped a cartridge
into his rifle, bringing the piece to his shoulder.

"Halt!" he challenged. "Who's there?"

The two figures, crouching low, made a bolt for the tall corn in a
vegetable garden at the rear of the grounds.

"As fast as he could shout the words Private Hal Overton shouted:

"Halt! Who's there? Halt! Who's there?"

Having obeyed a sentry's instructions to challenge three times, and
receiving no answer, Hal pressed the trigger.

A flash of flame lit the darkness around the rifle. It leaped straight
from the muzzle.

Bang! The bullet sped in among the corn stalks.

Over it all sounded Hal's voice:

"Corporal of the guard, post number three!"

Hal shot back the bolt of his rifle, dropping in a cartridge with
fingers as steady as at drill.

"Corporal of the guard, post number three!"

The gate was too far away. Hal took the fence at a bound, carrying his
cocked piece with him.

Straight to the growing corn the young private took his speedy way.

"Come out and show yourselves, or I fire at once," Private Overton
shouted.

Crack! crack! Two pistol shots rang out from the corn patch.

CHAPTER XXI

THE DUEL IN THE DARK

ALL this had occupied but a few seconds.

Private Hal Overton was on d