Bob’s eyes widened. “What’s that all about?”

It was an hour after dinner, and the boys had met again in Headquarters to discuss their plans.

“After you went home to change, Bob,” Jupiter explained, “we received a mysterious telephone call.” He told Bob about it, repeating the message word for word.

“Sounds like a gag to me,” Bob said, at last. He licked his lips. “If it’s not, somebody is telling us we’re not wanted near that cave.”

Jupe’s face had a familiar stubborn look. “We haven’t seen anything of the mysterious dragon yet,” he said. “I suggest we go back tonight for another look.”

“Let’s vote on it,” Pete suggested hastily. “My vote is we abandon the case now. All in favour say aye!”

“Aye! Aye! Aye!” The word was repeated shrilly by Blackbeard, the trained mynah bird whose cage hung near the desk in Headquarters.

“Quiet, you!” Pete snapped. “You’re not a paid-up member of this club. We only allow you to live here!”

“Dead men tell no tales!” Blackbeard called out and laughed shrilly.

Bob turned to Jupiter. “Maybe that’s who you heard — Blackbeard.”

Jupiter shook his head. “No, Bob. It came from somebody who seemed to have trouble breathing and speaking. If it was done deliberately to create the effect of a dying man — or even a ghost — it succeeded. It was actually scary, wasn’t it, Pete?”

Pete shrugged. “No more than anything else that’s happened so far.” He pushed back his hair. “If I’m not grey yet, maybe I will be by tomorrow.”

Jupiter grinned. “You’re no more scared than any of us, Pete. You’re just putting on an act.”

“Want to bet?” Pete said.

Jupiter’s answer was to pick up the phone.

“I’m betting that when Worthington shows up for us in the Rolls-Royce, you’ll want to come along,” he said.

Less than an hour later, Pete looked out of the window of the smoothriding, gold-plated, luxuriously appointed old car. It purred almost silently along the Pacific Coast Highway heading for the outskirts of Seaside. Worthington, the tall and polite English chauffeur, was at the wheel, driving with his usual skill.

“Sometimes I wish you’d never won the use of this car in that contest, Jupe,” Pete complained. “When I think of all the trouble it’s got us into.”

“Out of, too, Pete,” Bob reminded him. “And when our first thirty days’ use of it was up, you weren’t too happy about it, either, as I recall.”

An English boy they had helped at that critical time had made the necessary financial arrangements for the continued use of the car. The Three Investigators had almost unlimited access to the Rolls-Royce, as well as the services of its driver, Worthington.

Pete leaned back against the leather upholstery and smiled. “I’ve got to admit this beats riding in the truck, not to mention walking.”

Jupiter had given the directions needed to get them off the highway and on to the narrow ridge road overlooking the beach at Seaside. Now he leaned forward and tapped the chauffeur’s shoulder,

“This will do fine, Worthington,” he said. “Wait for us here.”

“Very good, Master Jones,” the chauffeur replied.

The big Rolls-Royce with the huge old headlights shining into the night eased up to the side of the road.

The boys tumbled out. Jupiter reached back into the car for their equipment.

“Torches, a camera and tape recorder,” he said. “Now we’ll be prepared for any emergency, and be able to document it, as well.”

He handed Bob the recorder. “For recording any sounds of dragon, Bob, or ghosts who have trouble breathing and talking.”

Pete took one of the three powerful torches. Jupe put a coil of rope on his other arm.

“What’s the rope for?” Pete asked.

“It always pays to be prepared,” Jupiter told him. “It’s a hundred feet of light nylon. It should hold us if the other staircases have been tampered with and we have to get down from the cliff by our own means.”

They walked a little way along the quiet, dark street. Jupiter led the way to the staircase he had chosen for their descent. It was several hundred yards from the one that had collapsed under their weight that morning.

His companions joined him on the ridge and looked down. The beach appeared deserted. The rising moon cast a dim glow through light clouds. The soft hiss of the waves lapping the sand below was periodically drowned out by the roar of the breakers that loomed up dark and menacing beyond.

Pete licked his lips nervously, grasped the handrail of the old staircase, and stood still for a moment listening. Bob and Jupe listened, too.

All they could hear was the dull roar of the surf and the beating of their hearts.

“Well, good luck one and all,” Pete said tightly.

As the boys took the first step down, they felt certain they heard the ocean roar a little louder, as if in anticipation!

The stairs were dark and the salty night wind stung their faces. The towering cliff wall jutted towards the ocean, casting long, gloomy shadows on the moonlit sand.

The staircase held their weight, and they ran down the last few steps with more confidence, jumping off to the sand with relieved sighs.

Jupiter looked up. Only an occasional light was burning in the houses along the ridge.

They trudged along the damp dark sand and passed the old staircase that had collapsed under them earlier.

As they approached the cave entrance, they came to a halt, listening intently and looking about carefully.

No one, as far as they could detect, was moving inside or anywhere about.

Jupe looked up. The cliff wall jutted out blocking his view of the ridge. He scowled, feeling this was important somehow, but not sure why.

At last he nodded, “All clear.” They slipped quickly inside and again Jupiter paused to listen. Pete was puzzled Jupe was acting as if they were on a commando raid.

“Why the big act?” Pete whispered. “I thought this wasn’t supposed to be so dangerous,”

“It never pays to be careless,” Jupe whispered back. Pete flicked his torch on and let the light play on the walls of the cave. Then he lowered it to the ground ahead. He gasped in surprise.

“Do you see what I see?” he demanded. “The cave ends right there — just behind the pit. How did those two skin divers get out?”

Jupiter walked forward slowly and flashed his light around.

“It’s a smaller cave than I expected,” he said thoughtfully. “And that’s a good question, Pete. How did those skin divers leave? And where did they disappear to?”

They walked about and tested the cave walls.

“Solid,” Pete said. “That’s great!”

“What do you mean, Pete?” Bob asked.

“Don’t you get it?” Pete answered. “Look how small this cave is! And that pit is pretty small, too. What I mean is, no dragon could ever fit in here!”

Jupe looked puzzled. “And yet Mr. Allen said he saw a dragon come out of the sea and enter this cave under the cliff.” He looked intently down at the pit. “Those skin divers didn’t just vanish into thin air. We’ll have to assume there’s another cave entrance here somewhere. Or another opening somewhere in this cave. There may be other, larger passages running close by.”

“Wow!” Bob suddenly exclaimed. “I just remembered something!”

Quickly he told his companions what he had read in the library and heard from his father.

Jupiter’s eyes were thoughtful. “A tunnel, you say?”

Bob nodded excitedly. “It was supposed to be the first underground railway system on the West Coast. It was never all finished, but part of it was, and still exists. Sort of like a ghost railway.”

“That’s interesting, Bob,” Jupe said. “But that tunnel could be miles away. And we don’t know that whoever started the tunnel came this far with it, or started at this end.”