Evans wondered.

"I'll show you," Bob said. He leaned out the same window he'd climbed in through. "See?"

Pete and Joshua Evans leaned out.

They saw a series of stones projecting from the outside wall near the window. The stones made footholds and handholds going up from the window to the roof.

"I guess your ancestor had to have a way to reach the roof," Bob decided.

"Jupe got to the roof on those!" Pete cried, gaping.

Bob smiled. "The Purple Pirate was coming up, and we had nowhere else to go. I guess you can do a lot more when you're scared. But no one's chasing Jupe now, and he says there's no way he can climb down."

"Like my cat, Blackboard, in a tree," Mr. Evans said. "He can get up, but it takes the fire department to get him down."

"Maybe we'll have to call the fire department for Jupe," Pete said, giggling.

"I think a strong rope will do," Bob decided. "Do you have a rope in the tower, Mr. Evans?"

"I sure do. I'll get it."

Evans soon returned with the rope, and Bob and Pete climbed up on to the roof with it. Jupiter stood there in the now bright day looking out at the cove. He seemed to be watching the Black Vulture as it sailed by the small islands on its much postponed first ride of the day. Onboard, a larger than usual group of tourists, increased because of the delay, observed the attack of the two pirates acted by Jeremy and Sam Davis.

"Would you say," the stout First Investigator said as Bob and Pete came up, "that someone wearing boots would make a noise walking down wooden stairs?"

"I guess so, Jupe," Pete said.

"Usually plenty of noise," Bob added as he uncoiled the rope.

Jupiter nodded. "And you saw no one go in or out of the front door. Second?"

"Only the cat."

Pete told them both about the cat coming out just as Mr. Evans appeared. "You guys must not have closed the door all the way."

"That explains why our Purple Pirate thought we had escaped through the front door," Jupiter realized. "Or, to be more precise, why whoever it was thought he had successfully scared us out of the building through the front door."

"Lucky for us the cat was in the tower, then," Bob said.

"Luck," Jupiter said smugly, "is simply planning so well that you are ready to take advantage of events." Then he added, smiling, "But luck sure helps if you can get it!"

"And speaking about help," Pete asked, "you ready to get down from here. First?"

"I," the leader of the trio said, "am not climbing back down on that route for midgets and flies. I'm not at all sure how I got up here, but I know that as far as climbing down is concerned, I am ready to live up here permanently. You may ask Aunt Mathilda and Uncle t.i.tus to send up some food and my bed!"

"We could send for a helicopter," Bob said, "but I think a good rope will do."

"Rope?" Jupiter cried. "Do I look like Tarzan?"

"We just tie the rope around you," Bob explained, "and then you climb down while we hold the rope secure so you can't fall."

Jupiter looked at the rope, then looked over the side of the high tower. He shuddered. "Well, I suppose it's the only way short of living up here forever. Tie on your rope."

Bob and Pete tied the rope firmly around Jupiter's waist and then held it securely, their feet braced against the low parapet of the roof. Jupiter knelt on the parapet, facing them. Taking a deep breath, he gingerly lowered his legs over the side and groped his way down with the small foot and handholds. Moments later he was helped through the window below by Joshua Evans, and Bob and Pete swarmed down behind him. Once inside, they all hurried down to the first floor.

"You think that Purple Pirate just wanted to scare us out of the tower, Jupe?" Bob said.

"I'm convinced of it, Records."

Joshua Evans said, "Any idea who it was, Jupiter?"

"Well, sir, it wasn't Major Karnes - he's much too short. And his helper, Hubert, is much too big. I considered you a strong possibility - you're the right size - but you were out there with Pete."

"Lucky for me," Evans said with a laugh.

"It certainly rules you you out," Jupiter agreed somewhat humourlessly, "along with Karnes and Hubert. But the pirate could be almost anyone else - it's very hard to tell a person's actual size and build in that costume." out," Jupiter agreed somewhat humourlessly, "along with Karnes and Hubert. But the pirate could be almost anyone else - it's very hard to tell a person's actual size and build in that costume."

"And you're sure he only wanted to scare you away," Evans continued. "Why?"

"To search the tower for something he thinks is hidden in it somewhere."

"Hidden, Jupe?" Bob said. "I thought you were sure Karnes and his gang were digging for treasure or something."

"I'm convinced whatever they are after is not buried but simply hidden."

"Gosh, Jupe," Pete exclaimed, "then why are they digging?"

"I think," Jupiter said, "that if we all go down into the cellar again, I can tell you exactly why Major Karnes is digging, and where!"

Chapter 17.

A Surprising Discovery THEIR FOOTSTEPS ON the wooden stairs echoed loudly through the low, enclosed s.p.a.ce of the dimly lit cellar.

"Records," Jupiter said, "do you remember when we first heard the Purple Pirate down here?"

"Sure. We were back there in that storeroom. He growled right behind us, and we turned and saw him."

"Exactly." Jupiter nodded. "So the very first sound we heard was his growl behind us in the storeroom. But we all just heard what a clatter we made coming down those wooden cellar stairs. Why didn't we hear the Purple Pirate in his heavy boots?"

"Maybe he tiptoed real quietly," Bob said.

"It would be hard - those stairs are very loose and creaky," Jupiter said. "But I have another question. For you this time, Pete. Why didn't you warn us when the Purple Pirate came into the tower?"

"Because I didn't see him go into the tower."

"Exactly again," Jupiter said maddeningly. "So you saw no one enter the tower.

Bob and I heard no sound of boots coming down the cellar stairs, and the kitchen door was bolted on the inside. I know that because I tested it first thing."

"So?" Pete asked. "What does all that mean, First?"

"It means," Jupiter said, pausing as usual for effect, "that the Purple Pirate who attacked us did not get into the cellar by coming down the stairs from the first floor, and did not get into the house through any entrance on the first floor."

"But there isn't any other way to get into the tower or the cellar," Bob said.

"There must be, Records," Jupiter insisted. "There must be some way of entering the tower and the cellar directly from the outside. And that's why Karnes and his gang have been digging!"

"They're digging a tunnel into the cellar!" Bob guessed.

"No, not digging," Jupiter corrected him. "Probably clearing out. Remember all those miraculous escapes of the Purple Pirate in the old days, fellows? He must have had an escape tunnel out of the tower. Somewhere in this cellar there must be an old tunnel to the outside!"

Joshua Evans said, "Jupiter is absolutely right, boys. There is an escape tunnel out of this cellar. It would have to be dug out, I guess. It was supposed to have collapsed years ago. The only thing is, I've never known exactly where it is."

"Then let's find it," Pete exclaimed.

Eagerly the Investigators and Mr. Evans spread out across the cellar and began to study the old walls. They tapped on them with pieces of pipe and boards they found in the storeroom, and looked for any signs of loose stones or hinges.

"Look on the floor for footprints," Jupiter instructed. But the dry clay of the cellar floor was far too hard to reveal any footprints.

"Here!" Joshua Evans cried.

He struck some stones again as the boys gathered around him. Almost directly facing the stairs, the wall gave off a faint hollow sound. There seemed to be an empty s.p.a.ce behind the stones for sound to echo in. But as closely as the boys looked, they could see no sign of a door or of loose stones. Jupiter slowly surveyed the dim cellar.

"The tunnel was meant to be a secret escape route, so its door would be well hidden. But the door would have to open from this side-and open fast. The Purple Pirate would need to leave in a hurry if he needed to use the tunnel at all. He would have to come down the stairs, and he'd want to open the door as quickly as possible.

Try the stairs."

They examined every Step of the wooden stairs, carefully studying the stone wall above and below. Pete found a small iron ring under a step halfway down. The ring pulled a single flat stone out of the wall. In the s.p.a.ce behind the stone was a large, well-oiled iron lever. When Pete pressed the lever down, the section of wall facing the stairs silently slid open!

"Well, I'll be!" exclaimed Joshua Evans. "All this time and I never never knew I had a knew I had a secret doorway right here!"

Mr. Evans got a torch from the storeroom and led the boys into a narrow tunnel just wide enough for one man and high enough for Pete to barely stand up straight.

On the wall just inside the tunnel was another lever.

"That must be for opening and closing the door from inside the tunnel," Jupiter noted.

The pa.s.sageway had a vaulted stone ceiling and stone walls and a dirt floor. All along its length stones had fallen from the walls and the ceiling. After some twenty metres the whole tunnel had collapsed.

"My father told me it fell in before I was born," Joshua Evans said. "Probably in one of the big earthquakes."

But the tunnel was no longer blocked. A pa.s.sage wide enough for even a large man to crawl through had been dug through the debris at the top. The Investigators and Evans crawled through one at a time and emerged on the far side. More fallen stones littered the pa.s.sage as it continued darkly ahead, and some twenty metres farther on it ended at four heavy, rough-hewn boards with rusted iron cross-braces. The four vertical boards were hinged at the bottom to a timber set in the dirt floor, and attached to beams on either side by two bra.s.s bolts.

Pete and Bob slid open the bolts, and the four boards lowered outwards like a drawbridge. Everyone walked forward and Joshua Evans' torch glinted on dark, black water! Ahead, the tunnel seemed to continue with wooden walls and ceiling and a water floor.

"We're inside the boathouse under the pier!" Jupiter cried.

"By thunder, you're right," Joshua Evans said.

"The only way out is to swim," Bob added.

"Uh, it's probably shallow enough to walk in," said Pete, red-faced, remembering his experience at the abalone pier.

"We'd better close the entrance to the tunnel behind us," Jupiter said. "We don't want Karnes or anyone else to know we've found it."

Bob and Pete pushed the four hinged boards back up and closed the bolts from the back by sliding protruding wooden pegs into place.

"Gosh, no wonder we missed this door earlier," Bob said. "No one could tell it isn't just four boards holding up the pier."

Joshua Evans and the boys waded out and climbed up on to the pier in the dim boathouse. Only a little sunlight filtered through cracks in the wall and the single dirty window in front. As they walked out through the double doors, Jupiter looked back thoughtfully.

"Bob's right - there's no way anyone could discover that tunnel by accident.

Which means that Major Karnes had to know it was there, and perhaps exactly where it was."

"Remember that doc.u.ment he was studying in the store?" Bob said. "I bet it was a map with the tunnel on it."

"Perhaps, yes," Jupiter agreed.

They walked through the grove of oaks to the Black Vulture, which had just returned from the first show of the day. Captain Joy, Jeremy, and Salty Sam were still on deck. Captain Joy was alarmed when he saw Joshua Evans with the Investigators.

"I told the boys to stay-"

Mr. Evans smiled. "It's all right, Joy, I know what the boys are doing now. It seems as much in my interest as anyone's to solve the mystery of what this Major . . . Major ..."

"Karnes, sir," Jupiter supplied, and turned to Captain Joy. "When did you start the first ride today, sir?"

"Only about forty-five minutes ago," the captain said, glaring towards Sam Davis, who seemed very interested in the distance. "Thanks to Sam, we waited for him so long we finally had to start without him, but he arrived at the first island in the nick of time."

Pete could restrain himself no longer. "We found where Karnes and his gang are digging, Captain! And why they wanted you and Jeremy away from your place.

There's an old escape tunnel from the tower to the boathouse! They've been clearing it out!"

The boys went on to explain all that had happened that morning, including their pursuit by the man in the Purple Pirate suit.

Jupiter faced Sam Davis. "Why were you so late today?"

"Couldn't get my dang car started, if it's any of your business, young feller," the hefty sailor said. "Got so late I just skedaddled through the gate and on out to them islands."

"Where do you store the Purple Pirate costume, Captain?"

"Out there on the islands. We keep all the costumes in a shed out there. It's more efficient."