Once more the Colonel swung round, and Owen realised with a sickening feeling of dread that he was coming across to the spot where he was in hiding. Terror of discovery and what would follow almost rooted him to the spot, and it was fortunate for him that his enemy, happening to think of some other matter, returned to question the sentry again. Owen took full advantage of the respite. Darting along the wall, he did not halt till he came to the farther end, where a flanking tower was erected preventing farther progress. There he halted, looking about him like a hunted animal, while his ears caught the approaching step of the Colonel in the distance. His danger was imminent, and discovery seemed more than certain. He drew his sabre, and then thrust it back with a sharp cry of delight. For danger sharpens men's wits at times, and Owen's mind had suddenly returned to what he had seen that day. He ran towards the approaching step, tiptoeing over the grass which bordered the wall, and halted beside the big gun which had caught his eye. There was not an instant to be lost, and therefore without hesitation he unhooked his sabre and thrust it into the muzzle, lest it should strike later and attract attention. Then he sprang on to the wall, and thrust one leg into the gun. Leaning all his weight on his hands, he did the same with the other, and in less time than it takes to tell he was out of sight, swallowed by the gigantic weapon. What if it were loaded! What if this Colonel discovered him, and taking advantage of his position fired the gun! "It would come to the same in the end," thought Owen. "Anyhow, I am sure that I could not have found a finer hiding-place, while as for room, in here there is heaps. It is as I thought. The calibre is very much greater than one usually comes across, and the muzzle must measure quite two feet--ample room for a youngster like me. Hark! There he comes." He held his breath, for the sound of a footstep near at hand came distinctly to his ears. He heard the Colonel move along past the gun to the wall of the flanking tower, and then his steps as he returned. Evidently he was a little uncertain of the sentry's tale, for he stepped to the wall, and leaning his hand on the muzzle of the giant gun within which his prisoner lay he leaned over and peered into the darkness of the street below. "Not there. It is a good jump, and the fellow knows that I have given strict orders that none are to leave the palace," Owen heard him say. Then he raised his voice and called angrily to the sentry. "Over there!" he shouted; "the jailer is not here, and doubtless you have never seen him. Pass the word in that he is to be found and is to come to me without delay. See that the order is given."