afely hidden there,
slip a cartridge into the breech and open the magazine. If there is an
alarm, it will be your duty to keep anyone from using those rifles, and
whatever happens you will stick to your post till I call you."

"I understand. You can rely upon me," Guy answered shortly.

"When you are in position," Jack continued, "I shall sneak up to the gun
and cut the prisoners loose. I'd give you that part of the job, Guy,
old boy, as your father is there, but I have already been up there and
know the ground. When we are ready I will slip across to you, and tell
you how matters have gone. Then we will all cut away down the hill,
fetch Mrs Robb and the kid, and strike round into the camp. Is that
all clear?"

"As clear as daylight, old horse!" exclaimed Guy, with a suspicion of
excitement in his voice. "I'm ready now. Let us set about it."

Once more creeping forward on their knees, it was not long before Jack
had guided his friend to the important post he was to occupy. Then he
left him there, and, knife in hand, climbed up the hill.

The gun was now only a few yards away, and in little more than a minute
Jack was close to it. Dropping flat upon the ground for a moment, he
waited till Hans Schloss had moved out of sight. Then he scrambled
forward and hastily dived beneath the enormous weapon. On either side
of him were the massive wheels, and through the spokes Jack made out the
figures of two men.

Rising slowly, he gently pulled the sleeve of one, and whispered in his
ear: "Be silent for your life! I am a friend."

The man gave a start, and almost cried out. Then he turned his head and
answered: "Who are you? For God's sake rescue us!"

Jack recognised the voice as Mr Hunter's, and placing his lips close to
his ear, whispered: "I am Jack Somerton. Stand still. I will cut you
loose."

Feeling along the spokes, he soon found that Mr Hunter's wrists were
lashed together to the hub of the wheel. He severed the cord with his
knife.

Then he dived beneath the gun to the other prisoner, and having told him
who he was, and that his son was close at hand, set him free also.

A moment later they were ready to start, Mr Hunter and Mr Richardson
still standing against the wheels as though their lashings were secure.

"Hush, here comes the sentry!" Mr Hunter whispered as they were about
to leave their posts.

Jack at once lay down upon the ground, and, opening the magazine of his
rifle, slippe