He tumbled through the opening, and then Pete and Jupe slid through.
“Wow!” Pete exclaimed. “This is more like it!” This cave was very wide and high. It extended back as far as their torches could reach, running inland parallel to the first cave they had entered. The Three Investigators jumped to their feet to examine it.
As they did, they heard a slight rumbling noise behind them. They whirled, too late.
The secret rock opening had closed behind them! “Uh-oh!” Pete muttered. “That does it!”
“That’s what happened to Bob before. I’m sure we’ll be able to work out how it works later,” Jupe said. “Probably a simple leverage system. Let’s forget it now while we investigate this cave.”
Bob looked up at the high vaulted ceiling.
“Wow!” he gasped. “Look at the size of it, Jupe This might be the tunnel I read about!”
Jupiter nodded. “Possibly, Bob. But if you notice, the walls and ceiling are rough, unfinished rock, as any cave is. The tunnel you told us about was completed. It would be in a more finished condition, with concrete walls possibly and a paved flooring. Perhaps tracks, too. Or the bedding for them.”
He shook his head, and flashed his light about. “No, this looks like any large natural cave. There’s no entrance to the beach and water behind us, either. The walls appear solid all the way round. But let’s follow its course under the cliff. It may still lead us to the old underground railway tunnel you mentioned.”
“What I like about it,” Pete said, “is that there’s no way out to the beach. That means, there’s no way in for things like dragons!”
“Which means we’re in luck,” Jupiter said smiling.
“There’s one thing certain about this cave anyway. It happens to be large enough to contain a dragon or any other creature that size.”
“Thanks for reminding me,” Pete muttered. “I nearly felt good there for about half a second.”
The cave floor was fairly smooth and level and they advanced along it steadily. Then they stopped short.
The passage ended suddenly in a high, vertical grey wall.
“End of the road,” Pete said. “Looks like all we’ve discovered is the world’s biggest unused parking lot!”
Jupiter was pinching his lower lip and looking puzzled.
“What’s wrong, Jupe?” Bob asked.
“That wall ahead of us,” Jupe said. “There’s something about it that doesn’t look quite right.”
Bob and Pete flashed their lights on it, and shook their heads.
“It looks like a wall to me,” Bob said. “Naturally I’m as disappointed as you are. I wanted — ”
Jupiter had his eyes half closed and wasn’t listening. He peered closely at the wall and tapped it. Then he hit other parts of it, his ear close to the grey surface.
“It sounds funny, Jupe,” Bob said.
Jupiter nodded, frowning, then walked to the side of the cave and tapped the wall there.
“There’s a difference,” he said finally. “I can’t explain it exactly but — ”
“Oh, come on, Jupe,” Pete interrupted impatiently.
“If you can’t prove it’s not a wall, then it is. Let’s get out of here. I’m getting cold.”
Jupiter’s face lit up. “That’s it!” he exclaimed.
“Cold! The wall isn’t cold. But the sides of the cave are. Feel the difference for yourselves.”
Bob and Pete hastily compared the feeling of the wall and the sides of the cave.
“You’re right,” Pete admitted. “It’s not as cold as the sides of the cave. But what does that prove? Don’t forget it’s under some of those houses along the ridge. Maybe heat comes down from them and warms the wall a little.”
“Heat rises, Pete,” Jupe said.
“There may be another pocket or passage inside,” Bob suggested, “That could warm it, too, Jupe.”
Jupiter shook his head, his mouth forming the stubborn line they were accustomed to seeing when he disagreed with them.
He took out his pocket knife and started to scrape at the rough grey slab.
Pete laughed. “You’ll only ruin your blade trying to cut through that rock, Jupe. What you need is a small stick of dynamite.”
Jupiter ignored Pete’s remark and continued scraping away at the wall surfaces. He looked at his blade and saw lumpy grey particles clinging to it.
He turned to face his companions. His mouth was open with a triumphant smile as if he had something important to reveal. But as he looked over their shoulders, his smile faded.
“The cave,” he said hoarsely. “I d-don’t know how but it’s opening behind you!”
His companions whirled in disbelief. There had been no opening before. How could it be opening now?
They watched, with staring eyes, what had to be impossible!
The cave opened wider, slowly. It became somewhat lighter. They felt a breeze.
They stood staring, their hearts pounding wildly, as it continued to open. They could dimly see the sand now, and farther out, the darker line of the ocean.
Jupiter was the first to speak.
“Quick! We’ve got to get back into that smaller cave!”
The Three Investigators ran forward and threw themselves at the small rock that had opened for them before.
Bob pressed at it frantically with his hands. He hit it with his shoulder. Then he looked at his companions, his voice shaking.
“I–I forgot how I did it before. I can’t open it!”
“Impossible,” Jupe grunted. “It was just a matter of leverage. We can find the spot.”
He joined Pete in pressing and pounding the resisting rock, while Bob continued his own search for the pressure point he had found earlier.
Light suddenly flooded the cavern, and they froze. The cave opening was widening. And something was moving towards them. Something huge and dark from the sea!
Pete gripped Jupe’s shoulder. “Am I seeing things?” he gasped.
Jupiter, stunned, shook his head. His mouth was very dry and his eyes blinked rapidly. “No — ” Jupe replied hoarsely “ — it’s a dragon, all right!”
The monstrous serpentine shape came closer and they could see water glistening on its dark wet skin. The shadowy head was small and triangular, held high on a long, swaying curved neck. Its yellow eyes were fixed on the cave, and bored into them like twin headlights. It advanced, making a strange humming sound.
In another moment, it was close enough to block the cave opening. Its head dipped low and the boys saw its long forked tongue flick in and out, as if getting ready to taste them. It hissed. Its hum was like a longing sigh.
Frantically, they continued their efforts to escape from the cave, hitting and throwing their weight against the rock from every possible angle.
“A-a-a-agh!” The monster was entering the cave now and they could hear its rasping breath.
They cringed back against the rock as the terrifying dragon loomed high above them. Then the long curving neck swung round and the dark head with its great staring yellow eyes lowered.
The long wet jaws opened and they saw its teeth, incredibly large and shining. It breathed again in its harsh rasping manner, and then it coughed and stopped.
Jupiter had read of the warning cough of the great jungle tiger as it prowled for prey. But he had never thought much about it. He remembered it now and shuddered.
His eyes were riveted on the dark head of the monster. It swayed back and forth hypnotically. Then, suddenly, it dipped closer towards them. Jupiter shrank back against his companions, his hands still frantically searching for the trigger point of the stubborn, unyielding rock behind him.
The dragon’s wet jaws loomed closer. Now they opened again and the frightened boys felt its hot steaming breath.
Suddenly the rock behind them clicked and trembled. Jupiter turned as it opened and saw Bob fall through. Pete sat frozen, staring helplessly up at the dragon. Jupiter jerked his arm and shoved him through after Bob. Then, holding his breath, he hurled himself through the narrow opening.
