The boys froze on the steep slope and looked back. The three menacing cowboys had left the road and were standing close to the dam.
“They’ve seen us!” Diego wailed.
“And too soon!” Pete groaned.
Even as the boys watched, the three cowboys began to run across the low, soggy mound from the corner of the dam towards the ridge.
“What do we do, Jupe?” Bob cried. “They’ve got us cornered up here!”
“I… I… ” Jupiter faltered.
A strange noise filled the air through the pouring rain and the steady surging of the creek — a roaring sound that seemed to grow louder as each second passed. It came from somewhere above the dam, from the flooding upper creek, and rushed closer and closer and closer. Halfway across the muddy mound between the dam and the ridge, the three cowboys stopped and listened, too.
“Look!” Pete yelled.
A wall of water crested ten feet above the dam!
“Something’s let go upstream!” Diego cried.
Filled with brush, logs, boulders and whole trees torn up by the roots, the massive wave poured over the dam and crashed down into the already boiling torrent of the lower creek. The whole rocky ridge on which the boys stood seemed to shudder. On the opposite bank of the creek, sliding mud carried brush and trees down into the water.
“Fellows! They’re coming again!” Diego yelled.
The three cowboys were running towards them across the mound. The boys started to flee, but stopped when they saw the long mound seem to split in half below! A huge section of muddy earth slid down into the boiling creek — taking the three cowboys with it! Flailing wildly, shouting and swearing, half swimming and half hanging on to debris, the cowboys were swept downstream in the raging torrent.
“They’re gone!” Bob exulted.
“Not for long,” Jupiter declared. “They’ll crawl out downstream, and be between us and the county road! Let’s move!”
Pete led the way up the slope to the great rock of Condor Castle. They climbed up over it and started down the other side. On both sides of the ridge, mud and boulders had slid down in the heavy rain, exposing new boulders and rocky outcroppings below Condor Castle.
“Wow, the mud’s sliding everywhere!” Pete exclaimed as he led the way down the steep, slippery slope.
The athletic Second Investigator leaped over a large row of exposed boulders. The others climbed up the boulders behind him—and stopped, gaping.
Pete was gone!
Pete had vanished as if the ridge itself had swallowed him up!
“Wha-what?” Diego stammered. “Where did he go?”
“Pete!” Bob cried.
“Second! Where are you?” Jupiter called frantically.
They anxiously searched the slope with their eyes, but nothing moved. Listening hard, they finally heard something. A voice that seemed to come from nowhere!
“Fellows! Down here!”
It was Pete — and his muffled voice seemed to come right out of the ridge!
“Where are you, Pete?” Diego called.
“Down here! Look right in front of those big boulders!”
The three boys jumped down in front of the exposed boulders and saw a long, narrow hole in the slope! A hole that was all but invisible until they were right on top of it! It hadn’t been there before.
“A mudslide must have uncovered the hole!” Bob realized.
Jupiter bent down to the long, narrow slit in the ridge.
“Second? You need help to get out?”
“I don’t want to get out!” the disembodied voice of the Second Investigator said. “It’s a kind of cave, Jupe! There’s loose rocks down here. We could block up the hole and those cowboys would never spot us! Come on down.”
The three boys on the slope looked at each other.
“Well — ” Jupiter hesitated.
“Come on!” Pete urged. “It’s dry and roomy, and those guys could come back anytime!”
That reminder was all the other three needed. Bob slipped down into the narrow hole first. Jupiter followed, grunting with the effort. The stout boy stuck halfway into the narrow opening!
“I… I can’t fit down — ” he said, red-faced.
From inside the cave Bob said, “Diego, push him! We’ll pull!”
Hands grabbed Jupiter’s legs. Out on the slope, Diego gripped the stout leader’s shoulders and pushed. With a loud sound, almost like the popping of a cork from a bottle, Jupiter slid down and vanished. Diego jumped through behind him.
Bob already had his torch on in the dark hole.
“Gosh!” Diego said as he looked around. “I never knew there was a cave here.”
The light showed a small, rocky space about the size of a one-car garage, with a low ceiling and loose rocks and boulders strewn around the floor. The cave was still dry despite the heavy rain now coming through the hole in the ridge. It had obviously been open only a very short time.
“Shine the light around, Records,” Jupiter commanded.
The small, low cave extended back some ten or fifteen feet and ended in a pile of loose rocks that rose to the ceiling. Jupiter examined the exposed entrance and slowly nodded.
“It looks as if it was covered up sometime in the past, fellows, probably by an earthquake. Rocks rolled down the — ”
“Never mind how it got covered up,” Pete exclaimed nervously. “A mudslide opened it, and those cowboys could spot the hole the same as we did! Let’s block it up!”
“There’s plenty of loose boulders,” Diego pointed out.
The four of them rolled and heaved at the biggest rocks they could move, and finally shut out the grey light of the late afternoon. With the opening closed off, no more rain came down into the cave. The four boys sat back and grinned at each other.
“We’ll wait a few hours,” Jupiter decided, “and by then those cowboys should have given up and gone.”
“I still wonder who they are?” Bob mused.
“They must have some connection with Mr. Norris,” Diego said grimly, “or why would they have stolen Pico’s hat and put it out near that campfire?”
“If they did,” Jupiter said. “We only know that they were looking hard for the car keys that Bob and Pete found in the barn. I wonder why we haven’t seen them with a car?”
“Well,” Pete said, “they sure want those keys, so the keys must prove something bad.”
“Yes,” Jupiter agreed. “Perhaps they — ”
“Ju-Ju-Jupe!”
It was Bob who began to stammer. He was shining his torch towards the rocks at the rear of the cave.
“That… that… rock,” Bob went on “It’s got… it’s… got — ”
“Eyes!” Diego gulped. “Eyes and… teeth!”
“A skull!” Pete moaned.
Jupiter stared at the pile of rocks. He blinked, and then his eyes seemed to light up. He hurried towards the
