“Oh, it’s there, is it?”

“Why---I---I------- Say, you’re trying to play a joke on me.”

“I rather think you’ve played it on yourself,” jeered the guide.  “Where did you leave it?”

“Right there, I tell you.”

“Sure you didn’t throw it over in the bushes down the other side?”

“I guess I know what I did with it,” retorted Chunky indignantly.

“Well, it isn’t here.”  Dad was somewhat puzzled by this time.  He saw that Stacy was very confident of having left the gun at that particular place, but it could not be found.

“Maybe somebody’s stolen it,” suggested the boy.

“Nonsense!  Who is there here to steal it, in the first place?  In the second, how could any one slip in here at the right moment and get away with your rifle?”

“You have no—–­no idea what has become of it—–­no theory?” asked the Professor.

“Not the least little bit,” replied the guide.

“Most remarkable—–­most remarkable,” muttered Professor Zepplin.  “I cannot understand it.”

“We’ll look around a bit,” announced Dad.

The three men searched everywhere, even going all the way down to the base of the rise on either side, but nowhere did they find the slightest trace of the missing rifle.  After they had returned to the summit, Dad, a new idea in mind, went over the rocks and the ground again in search of footprints.  The only footprints observable were those of their own party.  There was more in the mystery than Dad could fathom.

“Well, this gets me,” declared the guide, wiping the perspiration from his forehead.  “This certainly does.”

“Is—–­is my rifle lost?” wailed Chunky.

“I reckon you’ll never see that pretty bit of firearms again,” grinned Jim.

“But it must be here,” insisted Stacy.

“But it isn’t.  Fortunately we have plenty of guns with us.  You can get another when we go back to camp.”

“Yes, but this one is mine-----”

“Was yours,” corrected Nance.

“It is mine, and I’m going to have it before I leave this miserable old hole,” declared the boy.

“I hope you find it.  I’d like to know how the thing ever got away in that mysterious manner.”

“Maybe the lion took it.”

“Mebby he did.  Funny I hadn’t thought of that,” answered Nance gravely.  Then both he and the Professor burst into a shout of laughter.

They made their way slowly back to the point where they were to meet the others of the party.  Chunky, now being without a rifle, was well content to remain with the guide and the Professor.

While all this was going on Tad and Walter were picking their way over the rough ridges, through narrow canyons, riding their ponies where a novice would hardly have dared to walk.  The ponies seemed to take to the work naturally.  Not a single misstep was made by either of them.  They, too, could hear the dogs, but the latter were far away most of the time, even though, for all the riders knew, they might have been just the other side of the rocky wall along which the two boys were traveling.