“When the girl was about fourteen there was trouble about a pin Miss Jensen couldn’t find. She said the girl must have taken it, and she sent the girl back to her parents in disgrace. I heard the girl ran off with some scoundrel some years after. He left her eventually. She was living in San Francisco, last I heard, working in a market.”

Mrs. McCarthy put eggs and toast and bacon in front of Marilyn and the boys, then sat down herself to have a cup of coffee.

“Have you ever heard that the house is haunted?” asked Jupiter. “With all that trouble, weren’t there ever rumors?”

“Well, people do talk,” said the housekeeper. “But people always talk about old houses. I don’t know. I’ve never seen anything, but the place is unlucky. And sometimes, when the weather’s gray, I get a feeling that there’s something… something that watches me. It’s — it’s nothing I can put a name to, but I’d not stay here at night, I’ll tell you that!”

“Oh, nonsense!” said Marilyn.

“Have you ever heard anything walking around in the attic?” asked Bob.

“In the attic? No. I’ve never heard anything at all — not in the attic or anywhere else. It’s just that I’m… I feel as if something’s here somewhere.”

She sipped her coffee and looked gloomy.

The boys let the subject drop. Mrs. McCarthy couldn’t help them. But it seemed clear that last night’s creepy incident was something new in the house.

When breakfast was over, the boys took themselves off to The Jones Salvage Yard, where they reported to Aunt Mathilda.

Jupiter expected his aunt to be curious about the Pilchers, but that day Aunt Mathilda had no time for curiosity. An old brick building in Pasadena was being demolished, and Uncle Titus had just brought in a load of used bricks from the site. Aunt Mathilda directed the boys to clean the bricks, knocking off any bits of mortar that clung to them. Pete joined Bob and Jupe shortly before eleven and helped them pile the clean bricks in a neat heap near some ancient timbers. When they finished with the bricks, the boys went across the street to the Jones house. They washed up and then made sandwiches, which they carried to Jupe’s workshop.

The workshop was in a corner of the salvage yard well away from the office and the front gate. It was sheltered by an overhang that ran around the inside of the fence. Jupe had his workbench there and a small printing press that he had repaired when it came into the yard as junk.

The Three Investigators were munching away when a light over the workbench began to flash, signaling that the telephone in Headquarters was ringing. Jupe quickly pulled aside a grating that appeared to be leaning against the bottom of the workbench. Behind the grating was the open end of a huge galvanized iron pipe. This was Tunnel Two, one of the secret passages that the boys could use to enter their headquarters unobserved.

Jupe was a pudgy boy, not built for negotiating tight places. But he could get through the pipe in nothing flat when there was a call for The Three Investigators. He bent double now, ducked into the pipe, and scrambled through so quickly that the phone was only on its fifth ring when he pushed at the wooden trap door at the far end of Tunnel Two. It swung up to let him into Headquarters.

He picked up the telephone as Bob and Pete came into the mobile home trailer behind him. The call was from Raymond Sanchez, Jeremy Pilcher’s secretary.

“Marilyn asked me to call you,” Sanchez said. “We’ve been looking for that mysterious book all morning, and we can’t find anything. Marilyn thinks that if I boot up her father’s computer so we can look at his files, we may learn something. Only we don’t know the password that will get us into his files.

“Marilyn wants you to come. Maybe you can guess what the old goat — er, what Mr. Pilcher would have used for a password.”

Jupe turned to Bob and Pete and repeated Ray’s message. “What do you say? Want to go over to Marilyn’s and see if we can guess the password?”

“Yeah,” said Pete. “Okay, I guess.”

Bob nodded.

“We’ll be right there,” Jupe told Sanchez.

He hung up. “Sounds like our client has accepted us,” he said.

“I’m not sure I’ve accepted her,” said Pete. “She can be almost as prickly as her old man.”

But Pete followed Jupe and Bob out of Headquarters. In minutes the Three Investigators were ringing the bell at the Pilcher house. Mrs. McCarthy opened the door for them. She had a spray bottle of window cleaner in one hand and a roll of paper towels tucked under the other arm. “Just going to get a few things cleaned while the old grump is out of the way,” she said cheerfully. “When he’s around, I can’t do it. You boys come along. Marilyn and Ray are in the computer room.”

They went up the stairs behind Mrs. McCarthy. At the top she gestured them forward, then vanished into one of the cluttered bedrooms.

In the computer room Ray Sanchez was seated in front of the smaller of the two computers. Keys clicked under his fingers. The computer beeped.

Marilyn stood behind Sanchez and watched the monitor.

“This is Dad’s private computer,” she told the boys. “The big one is part of the system that’s been installed in Dad’s office downtown, but this smaller one isn’t part of any system. It doesn’t have a modem, so nobody from outside can get into the memory. If we can figure out the password, we can look at Dad’s private files. We might find that ‘bishop’s book’ is just a code name for something else.”

Sanchez shook his head. “All this stuff about a book is bilge,” he said. “I’ll bet somebody with a grudge against Pilcher set up the kidnapping. Lots of people would be ahead if Pilcher disappeared. Or maybe he decided he’d just drop out of sight for a while. He’s a weird guy. He could have his reasons.”

“He’s your boss,” Marilyn snapped. “Have some respect!”

“Sorry,” said Sanchez. He turned back to the keyboard. “Mr. Pilcher collects information on his associates,” he told the boys. “He checks out backgrounds and private lives and everything. I should know. Sometimes the background check means there’s a private investigator involved. I took care of paying some P.I.s’ bills, but I never got to see their final reports. I know some of the stuff Pilcher gets is too hot to go into the company files downtown. Maybe he puts it in this machine. But a bishop’s book? He didn’t know any bishops.”

“A code name,” insisted Marilyn. “It could be a code name.”

“Well, it isn’t the password, we know that,” said Sanchez. “I tried that and got zilch.”

He thought for a minute, then typed in the word HUSTLER.

“Hustler?” said Pete.

“You know about hustlers, don’t you? They pretend they don’t know

how to play a game, and they lure unsuspecting marks into playing with them. Then — whap! They win, and win big! That’s the kind of setup Mr. Pilcher likes. It’s the reason he sometimes employs people who have shady backgrounds. He’s more comfortable when he can hold things over people.”

“That’s only smart, isn’t it?” said Marilyn Pilcher.

No one answered her.

The computer beeped, and a message appeared on the monitor: INCORRECT PASSWORD. TRY AGAIN.

CON ARTIST typed Sanchez.

Again the machine beeped and the message INCORRECT PASSWORD appeared.

“You really are a — a rat!” cried Marilyn.

“We can stop anytime,” said Sanchez coolly. “It was your idea!”

“We can’t stop!” Marilyn insisted. “We have to know. But you needn’t be so insulting. You know business is a game to him. He’s like a high-pressure football coach. Would you like it better if he said a lot of corny stuff about always playing fair? No! You’d think he was a wimp, and you’d be right. Winning! That’s what counts, and you know it!”

Jupe had been watching quietly, his eyes almost sleepy. Now he suddenly came to attention. “A game,” he said. “Your dad talked about business as a game? Could that be a clue to the password?”