“Plenty o’ time, Sir Edward,” he said coolly, “if you’ll now order us back.”

The order was given, and as it was obeyed, Sir Edward and his son retiring last, they saw Nick Garth step close up to old Dan and pat him on the shoulder.

“You’re a cool one, mate,” he said. “I never see one as cool as you.”

Dan chuckled a little, and all went along the narrow passage and into the chamber beyond, well out of reach of the blast, and waited.

It was a good two minutes before the explosion took place, and Mark had made perfectly sure that the fuse had gone out, when there was a sensation as if his breath was being sucked away, then a deafening roar, followed by a crash.

Again they had to wait till the fumes had somewhat dispersed. Then, with Sir Edward and Mark leading, they returned, expecting to see the wall demolished; but as far as they could see it was perfectly sound, while another huge mass from the roof had come down, to lie piled up before it, so that there was hardly room for a man to crawl over the heap, so close was it to the roof.

“It’s of no use, Mark,” whispered Sir Edward, as they drew back a little from the smoke, “we must devise some other plan. It is useless to try another bag there without first clearing away the mass of stones, and we can only do that at the expense of many men wounded by pike-thrusts, perhaps killed.”

“Yes,” said Mark, “and it doesn’t seem fair to order them to do it.”

“I cannot, my boy. There, we have done our work for this time. Let’s get out of this horrible smoke.”

“Hoi, you!” came from beyond the wall; “if you fire any more of that choke-dog stuff, I’ll give orders to my men to kill the prisoners, ’specially the girl.”