“Very well, then, you will follow me, and I shall leave you behind a boulder close to the sleeping Boers. When you are safely 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.