behind.”
Mr. Hitchcock nodded. “And was he actually the living descendant of the Carter who started the tunnel and lost his fortune at Seaside?”
Jupe smiled. “Yes. But although he knew there was a tunnel, he never did find out exactly where. That’s why he knew about the first cave, and the boards leading into the next one. He was constantly snooping round there, and was more of a problem and worry to Shelby and the Morgans than we were. I suppose that’s why he always carried his shotgun with him, because he suspected something was going on.
“After the staircase near his house collapsed, he got suspicious again and went down to investigate. That’s when he nearly ran into Pete.
“Mr. Shelby told us the boards in the first cave had evidently been put in a long time ago by smugglers or pirates. He assumed they had built the moving rock. He found it by accident, just as we did. He added the newer plywood pieces himself when some of the old boards rotted. He was afraid somebody else would discover the moving rock and then the big cave and tunnel. He must have been saving the moving rock for a private emergency exit, because he never told the Morgan brothers about it.”
“And you helped Arthur Shelby return the gold bars to the bank vault?” Mr. Hitchcock asked.
“No,” Bob broke in. “He thanked us for the offer but said it was his own responsibility. He didn’t want to get us involved in any kind of criminal activity.
“He managed to get the gold bars back inside, and left them lying around carelessly as another kind of joke. Then he patched up the hole they’d made. I suppose the bank will eventually discover the tunnel underneath their vaults. But we haven’t told anybody else, not even Mr. Allen.”
Mr. Hitchcock nodded. “It is all certainly possible, given a man of Shelby’s considerable engineering talents. And it all came about because he knew the complete underground history of the city of Seaside.”
“Yes, sir,” Jupe said. “And the present-day history, too. So he knew exactly what banks were accessible from the tunnel all the time.”
“I see. One thing disturbs me. You allege my old friend Allen lied deliberately, saying he saw the dragon enter the cave, when it was impossible.”
“I’m sorry about that, sir,” Jupe said. “We found out later it was a simple mistake. He had been halfway down the steps that time, but had forgotten it in his distress at losing Red Rover. Is there anything else, sir?”
“No, boys. Though perhaps I should meet this Mr. Arthur Shelby. A man ingenious enough to scare you three lads is a man I could use. After all, you must remember, horror is my business, too.”
“Thank you, sir!” Jupiter cried, and Bob and Pete echoed the words. The First Investigator leaped to his feet. “We’d better get going. We’ve taken up enough of Mr. Hitchcock’s time.”
There was a flurry of happy boys, and then they had gone.
“Mmmm,” Mr. Hitchcock murmured to himself. “I wonder if I should borrow that ingenious dragon Mr. Shelby devised. Since I’ve just purchased that large bus-like trailer for my holidays, perhaps it would be a good idea if I learned how to double-declutch the dragon in the cave first, before I ventured forth on the Los Angeles motorways!”
