“I knew I could count on you, Mathilda,” Titus said. “The very thing! Hans — Konrad — finish unloading. Be careful you don’t chip them.”

He sat down in the shade, got out his pipe and started to light it as Hans and Konrad began lifting down the plaster busts.

“Those heads,” he said. “Found them at an old place in a canyon in the hills. Grand old house. The owner died. All the furniture and rugs were sold before I got there, unfortunately. Nothing left but some odds and ends nobody else wanted — these busts, some books, a sundial, some garden furniture. So I bought them.”

He fell silent, puffing on his pipe. Jupiter, Peter and Bob took the occasion to slip away. In a moment they were back in their workshop section.

“Whew!” Pete sighed. “I thought your aunt was going to keep us working all day, Jupe.”

“She would have if she hadn’t been afraid we might drop one of those plaster heads,” Jupiter replied. “Aunt Mathilda can’t bear to lose money on a deal.”

“What shall we do now?” Pete asked. “We haven’t any mystery to investigate. Let’s get out those maps of old ghost towns in the desert we’re going to explore some day.”

“Or we could work on that contest that offers a trip for two to Hawaii as first prize,” Bob suggested.

“Well —” Jupiter began. At that moment a red light, mounted on a board over their printing press, began to blink.

“Look!” Bob yelled. “A phone call!”

“It might be someone wanting a mystery solved,” Jupiter said hopefully.

Pete had already slid back the piece of iron grill-work that leaned against a box behind the printing press. He crawled inside the box and dropped down into Tunnel Two, a large corrugated iron pipe which led, partly underground, through a tangle of junk to the hidden mobile trailer. Bob and Jupiter followed him. Pete pushed open a trapdoor at the other end and they all climbed up into the tiny office of Headquarters.

The telephone was indeed ringing. Jupiter snatched it up.

“Hello!” he said. “Jupiter Jones speaking.”

“One moment, please,” said a young woman’s voice, which they could all hear through the loudspeaker attachment that Jupiter had rigged up. “Alfred Hitchcock is calling.”

Alfred Hitchcock! When Mr. Hitchcock called, it usually meant he had a case for them.

“Hello, young Jupiter!” Mr. Hitchcock’s rich English voice came booming into the tiny space. “I hope you aren’t too busy right now. I have a young man here who needs help, and I think you and your friends are just the ones to aid him.”

“We’ll be glad to try, Mr. Hitchcock,” Jupiter said. “What is your friend’s problem?”

“Someone has left him something valuable,” Mr. Hitchcock said. “Unfortunately, he has no idea what it is or where to find it. If you can be at my office tomorrow morning at ten, he’ll be here to tell you all about it.”

“TERRIFIC!” Pete exclaimed. “Mr. Hitchcock has a new case for us.”

“A boy who has been left something valuable and doesn’t know what it is or where to find it,” Bob added, frowning. “It sounds pretty mixed up to me.”

“The more baffling it is, the better,” Jupiter said.

“We’ll need a car to drive us over to Hollywood,” Pete put in. “I’d hate to drive into World Studios and up to Mr. Hitchcock’s office in the old truck.”

“I am phoning the Rent-’n-Ride Auto Agency now,” Jupiter told them, starting to dial, “to tell them we will need the Rolls-Royce and Worthington tomorrow morning.”

Some time ago, Jupiter had won the use of a genuine, gold-plated, antique Rolls-Royce, complete with chauffeur, in a contest. The car had been invaluable to them in their career as investigators, for distances in southern California are great, and it is almost impossible to cover them except by car. Of course, sometimes the three borrowed the salvage yard’s small truck, with Hans or Konrad driving. But for a visit to see Alfred Hitchcock, the famous director, a truck was hardly dignified enough.

“Hello,” Jupiter spoke into the telephone. “May I speak to the manager, please?...Hello, Mr. Gelbert, this is Jupiter Jones speaking. I wanted to tell you I will need the Rolls-Royce, with Worthington, tomorrow morning at nine-thirty.”

They were surprised to hear the man at the other end say, “I am sorry, but that will be impossible. Your thirty days’ use of the car has expired.”

“Golly!” Pete groaned in dismay. “We haven’t been keeping track. The thirty days ran out while we were back East tangling with the mystery of Skeleton Island.”

But Jupiter was speaking into the telephone again.

“According to my figures, Mr. Gelbert,” he said, “the thirty days still have some time to run.”

“But they don’t!” Pete whispered loudly. “The thirty days ran out. He’s right.”

The First Investigator waved his free hand at them. The manager of the rental firm was speaking again.

“I’m afraid you’re wrong,” he said firmly.

“Mr. Gelbert,” Jupiter said in a dignified voice, “I believe we have a difference of viewpoint here that needs to be straightened out. I’ll be at your office in twenty minutes to discuss the matter.”

“There’s nothing to discuss!” The man sounded annoyed now. “The time is up. Come down, but it won’t do you any good.”

“Thank you,” Jupiter said. He hung up and turned to the others. “We have to get our bikes and ride downtown.”

“But he’s right!” Pete protested as they crawled out through Tunnel Two. “Thirty days is thirty days.”

“Not always,” Jupiter said mysteriously. “Leave the talking to me.”

“We’ll leave it to you, all right,” Bob agreed. “We haven’t anything to say. I think we’re wasting our time.”

Jupiter would say nothing more. They rode out through the main gate, then cycled half a mile down the shore road into the heart of Rocky Beach. Off to their left the Pacific Ocean gleamed blue in the sunshine, its surface dotted with boats. To their right rose the Santa Monica Mountains, brown and jagged.

The Rent-’n-Ride Auto Rental Agency occupied a corner on the main street. The Three Investigators parked their bikes outside and walked in, Pete and Bob rather reluctantly following Jupiter.

They were shown into the manager’s office. Mr. Gelbert, a stout, red-faced man, scowled as he saw them.

“Well?” he asked Jupiter. “You won our contest and you had the use of the car for thirty days. Now what makes you think you can keep on using it? Can’t you count?”

“Yes, sir,” Jupiter said politely. “I’ve tried to be very accurate in my counting, Mr. Gelbert.”

From his pocket he took a small notebook and an envelope. He took a folded piece of paper from the envelope. It turned out to be a small handbill advertising the original contest which Jupiter had won.

It said:

“Humph!” Mr. Gelbert said, looking at it. “What are you getting at? You had the use of the car for thirty days, any day you wanted, and every day has twenty-four hours, so that’s that.”

“I want you to study the wording of your advertisement again, sir,” Jupiter said. “It says that the winner gets the use of the car for thirty days of twenty-four hours each.”

“All right,” Mr. Gelbert snapped. “You had it for thirty days and every day has twenty-four hours in it. Everybody knows that.”

“Exactly, Mr. Gelbert,” Jupiter Jones said. “Everyone knows a day has twenty-four hours in it, so why mention it at all? Why not just say, ‘Win the use of a Rolls-Royce for thirty days’?”

“Why — uh —” Mr. Gelbert spluttered. “I was just trying to make it sound more, well, more splashy and interesting.”