"Suppose, George, that somebody wanted to see the Curtis house, and yet not be seen, wanted to observe as well as he could, without detection, what was going on there. He'd watch his chance, jump over the fence as we have done and enter this group of pines. He could ask no finer point of observation. We are perfectly hidden and yet we can see the whole rear of the house and one side of it." "So we can. I infer that you are looking for some one who you think has been acting as a spy." "Ah! here we are. The earth is a bit soft by this pine, and I see the trace of a footstep! And here is another trace, close by it, undoubtedly the imprint of the other foot. It's as plain as day." Dalton knelt, looked at the traces, and shook his head. "I can't make out any of them," he said. "I see nothing but a slight displacement of the grass caused by the wind." "That's because you haven't my keen eye, an inherited and natural ability as a trailer, although you may beat me out of sight in other things. The shape of these traces indicates that they were made by human feet, and their closeness together shows that the man stood looking at the house. If he had been walking along they would be much wider apart." He examined the traces again with long and minute care. "The toes point toward the house, consequently he was looking at it," he said. "He was a heavy man, and he stood here a long time, not moving from his tracks. That's why he left these traces, which are so clear and evident to me, George, although they're hidden from a blind man like you." "Well, what of it?" "Nothing much to you, but a lot to me." He rose to his feet and examined the boughs of the pine. "As I thought," he whispered with great satisfaction. "Despite his courage and power over himself, both of which were very great, he became a little excited. Doubtless he saw something that stirred him deeply." "What under the stars are you talking about, Harry?" "See, he broke off three twigs of the pine. Just snapped them in two with nervous fingers. Here are pieces lying on the ground. Now, a man does that sort of thing almost unconsciously. He will not reach up for the twig or down for it, but he breaks it because it presents itself to him at the corner of his eye. This man was six feet in height or more and built very powerfully. I think I know him! Yes, I'm sure I know him! Nor is it at all strange that he should be here." "Shall we make a thorough search for him among the pines? You say he's tall and built powerfully. But maybe the two of us could master him, and if not we could call for help." "Too late, George. He left a long time ago, and he took with him what he wanted. We needn't look any farther." "Lead on, then, King of Trailers and Master of Secrets! If the mighty Caliph, Haroun al Kenton, wishes to prowl in these grounds, seeking the heart of some great conspiracy, it is not for his loyal vizier, the Sheikh Ul Dalton to ask him questions."