"They seem to be as high as they"re going to get," said Bud. "But this sure is queer! Hold your match closer, Nort."
Another of the tapers was lighted, and across the pool came the voice of Snake Purdee, asking what was going on.
"There"s some sort of a handle, or lever, here," answered Bud, as he examined it more closely. "It moves, too," he added as he laid his hands on it and pulled it toward him.
"Look out!" cautioned d.i.c.k, but it was too late.
Bud had pulled the copper lever toward him, and, in spite of its size and weight, it moved easily in what appeared to be a slot in the rock.
It clicked slightly, as though connected with hidden mechanism.
Then, with a suddenness that was startling, a low but ever-increasing roar seemed to fill the cavern in which was the black pool. The roar grew louder and louder, and the very rock beneath their feet seemed to tremble.
"What have you done?" gasped d.i.c.k.
"Search me!" answered Bud in such queer tones that Nort laughed.
And then a strange thing happened. As Nort struck another match he and the boys on the rock could see the water all about them beginning to recede. Slowly it flowed at first and then, with a rush, it began running out of the place as fast as it had run in.
"What"s up over there?" called the voice of Old Billee from "sh.o.r.e," so to speak. "What you fellers doin" with th" water?"
"I just pulled that lever," sang out Bud.
"Then you"ve done the trick!" said the old cowboy. "You must have opened some gate, and the water"s running away. Better swim over here while you have the chance. When the water comes back that rock may be covered!"
But another strange part of their mysterious adventures was that they did not have to swim back. For the water receded so rapidly that, in a little while, it was possible to wade from the rock to the stone edge of the pool where the other members of the party stood. And wade back to their friends Bud, d.i.c.k and Nort did.
"Oh, boy! But we"re glad to see you!" cried Old Billee, as he caught Nort by the hand.
"You let out a mouthful that time!" declared Yellin" Kid, and his voice nearly split their ear drums, so magnified was it by the echoing, vaulted roof of the cavern.
"But what all happened?" asked Snake Purdee. "Is there some old Mexican grain mill under here that has a water-wheel, sluices and gates?"
"I give it up," answered Bud. "All I know is that I pulled that copper lever--and it"s copper so it won"t rust off, I reckon--and the water began to rush out as fast as it must have come in here."
"It is mighty queer," agreed Old Billee. "Let"s go take a look," and he started to walk across the intervening s.p.a.ce between sh.o.r.e and the great rock--a s.p.a.ce in which only a few puddles of water now remained.
"Will it be safe?" asked Bud, who had begun to dress, an example followed by d.i.c.k.
"Why not?" asked Old Billee. "The water can"t rise any higher than it was when you fellows were on the rock. An", according to your tell, there"s room enough for us all t" stand there."
"Yes, it"s big enough," agreed Bud. "But suppose we all get there, and the water begins to come back?"
"We"ll turn it loose again with th" lever," answered the old cow puncher. "But I reckon it can"t fill up this pool again until that lever is shifted hack where it was before you yanked it."
"Maybe not," admitted Bud. "Well, let"s take a chance. If worst comes to worst we can swim back, and I"d like to solve this mystery. I feel that we"re getting at it now!"
"That"s right," said Nort, who was feeling stronger every moment.
"When I fell in, and was carried away," he said, "I had a wild notion that this might lead to the discovery of something. I managed to keep my head out of water as I was swept along, until I got a knock on the noodle, and that put me partly to sleep. That may have been a good thing, too, for they say a partly unconscious person doesn"t breathe much, and that"s why I didn"t swallow any water to speak of.
"I was dazed when I must have been swept, or floated, past that rock but I came to in time to save myself. Gosh! but I was glad to hear you yell though, d.i.c.k!" he said.
"Well, let"s get over there an" start pryin" out this secret,"
suggested Old Billee. "This is gettin" mighty interestin"!"
It seemed reasonable to suppose that the water would rise to no greater height than it had when the searchers had discovered Nort on the rock.
And as this boulder was well out of water, and large enough for them all to stand on, they would run no risk, even if the flood should start to return when they were in the middle of the pool, which, however, was a pool no longer, but merely a wet reservoir, so to speak.
"But I don"t believe the water will flow back here until you shift that lever again, Bud," declared the old ranchman. "And I"m going to have a try at it!"
"Isn"t it takin" a chance?" asked Snake.
"You got t" take chances in this world!" declared Old Billee.
"Well, let"s go!" suggested Bud.
"I think I"ll stay here," spoke Nort. "I don"t feel quite up to walking over those rocks. And you may need some one on this side who can throw a rope," he added, as he looked at the lariats.
"All right," a.s.sented Bud. "You stay here, Nort."
They left him on the sh.o.r.e, as I call the rocky edge of the pool, with a lantern, and, taking other lanterns with them, the little party set out. It took them only about three minutes to walk across to the great rock, which stood upright in the middle of the cavern floor.
Rising up in almost the very centre was the heavy, copper lever. By the light of the lanterns it was examined, and seen to extend down through the rock, whither no one knew.
"It works a water gate all right," declared Old Billee. "Let"s pull it back to where you found it, Bud, and see what happens."
It was with some feelings of apprehension that the others watched as Old Billee reached for the copper lever and pulled it toward him, It operated as easily as it had for Bud.
And almost as quickly as had taken place on the other occasion, there was that roaring, rumbling sound, a noise as of the blowing of a great wind, and then the waters began to rush back into the pool.
"Here they come!" yelled d.i.c.k, as he stood beside Bud on the rock.
Truly the waters were returning as the hidden gate was closed when Billee pulled the lever.
Would they go down again?
That was what each one asked himself.
CHAPTER XXIII
THE CONSPIRATORS
Rapidly rushing, foaming, bubbling and boiling, the waters rushed into the mysterious cavern, until they again filled the pool across which Bud and d.i.c.k had swam to the rescue of Nort on the rock. Now the situation was reversed. It was Nort who was on the mainland, or sh.o.r.e, so to speak, and the others who were on the rock.
But it was one of their own choosing, in an endeavor to solve the mystery, though as Bud and his companions watched the waters creeping higher and higher up the surface of the rock on which they stood, their hearts were not altogether easy.
"Suppose it covers the rock?" asked d.i.c.k.