For a moment or two both Rick and Chot thought that they had played a trick upon themselves, and that they were gazing upon the headquarters of Uncle Tod and Sam Rockford who might be entertaining guests. The same idea was in the mind of both boys. They jumped to the conclusion that they had circled about in the tunnel, had, somehow or other, gotten into the same shaft¹ they had first explored with Uncle Tod and so had doubled back on their trail.  
For there was almost the same outfit² as that at Uncle Tod’s camp—the log shack³, a tent—and, scattered⁴ about, were some mining implements⁵, while at one side a flume box had been set up.
 
But there was this difference—there was water running into this flume box, while back at Uncle Tod’s camp his box was dry.
 
It was this welcome sight of the much-needed water that first convinced the boys they were looking at another camp—a strange one—rather than at Uncle Tod’s, though both outfits⁶ were much alike. But one camp was dry and the other was wet. Lost River seemed to be favoring this camp as against the other.
 
Then, too, as the boys looked with less excitement pumping at their hearts, they noticed that all the men were strangers. Neither Uncle Tod nor Sam Rockford was among them, and no men that the boys had ever seen before, though they had met several friends of Uncle Tod and his partner.
 
Also, as their eyes took in further details of the strange camp, they saw very many points of difference. The log cabin was much smaller and was not so well built, nor was the tent the same. The flume box was much larger, though not so solidly constructed—in short hardly any details of the two camps were alike, though in general one resembled the other. Of course the men were totally different.
 
“It’s another place all right,” whispered Chot.
 
“Yes,” agreed Rick, while he cautioned Ruddy, in a low voice, to remain quiet. He did not want a whimper, whine⁷ or bark of his dog to betray their presence back there in the tunnel. “Did you think it was our camp?” asked Rick.
 
“For a minute I did,” assented⁸ Chot. “Didn’t you?”
 
“Yep. I thought we’d doubled back through the tunnel somehow.”
 
“So did I. But what’s it all about, Rick?”
 
“I don’t know, Chot. But I can make a guess at one thing.”
 
“What’s that?”
 
“Those are the men—or, anyhow, they’re in the same gang—that took away Lost River.”
 
“What do you mean—took away Lost River?”
 
“Look,” went on Rick, still speaking in a whisper. “You can see where the channel was, running right into this tunnel. There’s the old bed of the river. Now it’s running off to the left so it flows into their flume box. They changed the river, that’s what they did.”
 
“I believe you’re right,” said Chot, after looking over the outlay⁹ that was before them. They could see it well, hidden as they were just inside the tunnel entrance. “But how could they make a river run in a new place?”
 
“By making a dam, or digging a new channel. I don’t see that they have dug any new channel, so they must have built a dam, or some sort of thing to send the river down the way they wanted it instead of letting it come through the tunnel to Uncle Tod’s mine.”
 
“But where is the dam, or whatever it is? I don’t see anything like it here.”
 
“No, it’s probably up above their camp. We’ll have to prospect¹⁰ around a bit and find it.”
 
“S’posin’ they see us?”
 
“We mustn’t let ’em. We can mosey around after dark.”
 
“Then we’re going to stay here all night?”
 
“I don’t see what else to do. We could hardly get back to camp until very late, anyhow, and we’ve got our blankets and some grub. It won’t be cold in here.”
 
“That’s right! It’ll be fun!” exclaimed Chot.
 
“And we don’t want to go back and tell Uncle Tod what we’ve found until we can tell him everything,” went on Rick, who liked to be thorough and complete in his work or play.
 
“That’s so,” agreed his chum. “Maybe, after all, we’re up the wrong tree and these men didn’t change the river.”
 
“Oh, I think they did—or somebody in with ’em,” said Rick. “But I’d like to find the dam—or whatever it is—and then we can tell Uncle Tod and let him do what he thinks best.”
 
“I guess you’re right,” assented Chot. “Well, what’ll we do first, Rick?”
 
“Well, let’s just stay here and we can see what the men do. Maybe we can hear what they say.”
 
Ruddy had quieted down, now that he saw his boy chums had no present intentions of engaging in anything that needed his canine¹¹ wit, and was str............