y advancing towards the building, his feet crunching heavily into
the gravel and giving the sentry every warning of his approach. The
sentry watched him with lazy indifference, but, as he drew near, lifted
rifle and bayonet and challenged.

"Who comes there?"

"A workman with message to the engineer," responded Max in a casual
voice, slackening his pace and coming to a stop a few paces away.

"Pass," replied the sentry indifferently, letting the butt of his rifle
drop again to the ground. Max slouched on again, directing his steps so
that he would pass just in front of the young soldier.

The sentry idly watched the supposed workman, who slouched along gazing
at the ground in front of him in the most stolid fashion. Just as he was
on the point of passing the sentry, however, he shot out a hand, seized
the man's rifle, and tore it from his grasp.

Simultaneously a hand appeared from behind, and a cloth was clapped over
the soldier's nose and mouth and held firmly in position, while another
hand and arm grasped him round the middle.

[Illustration: A CLOTH WAS CLAPPED OVER THE SOLDIER'S NOSE AND MOUTH]

Noiselessly grounding the captured rifle, Max in his turn sprang upon
the sentry and wound both his arms about him, crushing his arms to his
side and preparing to subdue his wildest struggles. Almost immediately,
however, the man's muscles relaxed, as the chloroform, with which the
cloth had been sprinkled, took effect, and Max and Dale lowered him to
the ground.

"Now, Dale, off with his tunic and helmet and put them on," cried Max
rapidly. "Then take his rifle and stand on guard. All is well, and I
believe we shall win through without a hitch."

Dale did as he was bidden. The soldier's tunic and helmet were removed,
and his body was dragged into the shadow close to the wall of the
building. Then Max walked quickly back to the spot where the shells had
been deposited. Here Dubec crouched in readiness.

"Bring them along," whispered Max. "The sentry is disposed of, and we
ought to meet with no interruption."

"'Twas splendidly done," replied Dubec with enthusiasm. "The man seemed
to be overcome as though by magic, and I heard scarce a sound."

In three trips the shells were transported to the power-house and laid
along the wall. Then Max went to one of the windows and looked in.

The power-house was largely underground, and the windows, which ran
around all sides on a level with the ground at intervals of abo