And walking and pausing by turns, the boy kept his watch, working hard to convince himself that he ought to be very proud of the confidence placed in him. "There's something so real about it," he thought. "It's quite grand marching round and round here with a loaded double-barrelled rifle over my shoulder. I wonder how old Dean will feel. I'll be bound to say he'll be just as squirmy as I was. He won't go to sleep the first time he's on the watch." The hours seemed to pass very slowly, though it was at their usual rate, and at last to his great satisfaction not only could he feel sure that half of his watch must have passed, but that it was growing lighter. It could not be the approach of dawn, for he could see a few stars peeping out here and there, and he realised that this was caused by the lifting of the mist under the influence of a light breeze that felt almost chilly. Mark was standing some little distance from the second waggon where the ponies were picketed, when all at once his heart set up its heavy beating again, for coming in his direction along the edge of the patch of forest he could plainly see a big, dark animal creeping cautiously towards where the ponies were tethered. Mark watched it for a few moments, till he felt that it must have passed behind the trunk of one of the larger trees, and then it was gone. "Could it be a lion?" he thought. "No, it had not the big, shaggy head. But it might have been a lioness, or perhaps some big leopard. Ah!" he panted, "there it is again! It's after the ponies. It must be!" and calling to mind that he had cocked his rifle, he covered the dimly-seen animal, which was coming very slowly nearer, and he could make out that it had moved on a few feet and then stopped, as if crouching down waiting to make a spring. "What did the doctor say?" thought Mark. "I was not to fire unless there was real necessity. There must be real necessity here, for that beast is creeping closer and closer so as to be within easy distance for its spring." The boy hesitated no longer, but raising his rifle to his shoulder he covered the object that was advancing, and was about to draw trigger when he realised the fact that he was aiming at what seemed to be a bush, while the lioness, or whatever it was, had disappeared. Mark stared in wonder, for he could not understand how it was that an object which had seemed so clear in the transparent darkness had disappeared so easily, and he was staring almost wildly in the direction where he had seen it last when there was a faint, rustling sound a little to his left, convincing him that the nocturnal marauder had passed a pensile bough of a tree that must be sweeping the ground, and must be close upon the ponies, one of which uttered a low, tremulous, whinnying sound, and gazing sharply in the direction Mark saw as he drew trigger the big animal assuming a rampant position in springing upon the pony.