This gate was made of heavy bolted planks and was set on hinges in a jamb of other planks and boards that closed the reservoir end of the tunnel water-course. A similar barrier and big door was at the Pocut River end. "Well, if he was here, he seems to be gone," observed Nort "Maybe it was a sheep herder, Bud." "Well, if any of that gentry think they can drive their flock over here, and water their woolies at my expense, they're mistaken," declared Bud with emphasis. "Sheep men have to be, I reckon, but they're out of place in a cow country. Hello, there!" he called, loudly. "Come on out and show yourself!" But there was no answer, and the only sound, aside from the creaking of the damp saddle leathers, was the splashing of water as it flowed from the big pipe and into the reservoir. "Guess he lit out," observed Bud, thrusting his gun back into the holster. "Or else you didn't see him," chuckled Nort. "Maybe your eyes are full of dust, same as mine are, from that round-up." "Oh, I saw somebody all right!" declared Bud. "Might 'a' been one of Buck Tooth's Indian friends making a call, but--" He suddenly ceased speaking and leaned over in his saddle to gaze earnestly at something on the ground. It was something that glittered and shone in the mystic moonlight as Nort and Dick could see. "What's that?" inquired the latter. In answer Bud slipped from his saddle and picked up the object which the moonlight had revealed. "What in the world is this?" asked the boy rancher, as he held up a curious instrument. "Is this the start of another mystery!" CHAPTER III STARTLING NEWS Leaping from their saddles, Nort and Dick hurried to the side of their cousin, chum and partner in the ranch venture. Eagerly they looked over his shoulder while he examined the strange object he had picked up, almost at the very door leading into the mysterious tunnel. The instrument--for such it seemed to be--consisted of a shiny, nickeled part, which was what had reflected the moonlight, thus attracting Bud's attention to it. In addition there were two flexible tubes, of soft rubber, joining into one where they met the shiny metal. The two tubes each terminated in hard rubber ends, pierced with a tiny hole, and on the end of the single tube was a bright metal disk. The whole formed a strange object, picked up as it was from the ground, and especially when the boy ranchers feared they had some cause for alarm. "What in the world is it?" asked Bud, as he dangled it in front of his cousins. "I never saw anything like it before. Wait! I have it! Yellin' Kid said he was going to send to Kansas City for a flute he could play on. This must be part of it! He dropped it here; though that couldn't 'a' been him sneaking around the tunnel. But this is Yellin' Kid's musical instrument all right! Oh, won't I rag him, though! I wonder which end you blow in?" "That isn't a musical instrument!" declared Nort, taking it from Bud's hand.