“Okay.” The other boy hung up and Bob put the phone back in its cradle. Then, not having anything else to do until it rang again, he sat down at the typewriter and typed all his notes on the case so far. When he had finished, he looked at his wrist-watch and saw that it was almost noon. There hadn’t been any more calls. This time the Ghost-to-Ghost Hookup was a failure.

“Bob! Bob Andrews!” Mathilda Jones’s powerful voice came in through the open skylight. “Jupiter isn’t back but lunch is ready. You might as well eat.”

“I’ll be right there,” Bob called into the microphone.

He started for Tunnel Two and had the trapdoor open when the telephone began to ring. He scrambled back, grabbed up the phone and breathlessly said, “Hello! Three Investigators. Bob Andrews.”

“You wanted to know about a bust of Octavian,” a girl’s voice answered. “Well, my mother has it, but she tried putting it in the garden and she thinks it looks silly. She said she’s going to give it away to a neighbour.”

“Please don’t let her do that!” Bob cried. “Our motto is that every customer must be satisfied. We’ll come out to your house just as soon as we can and refund her money. I’ll also bring another bust in case she thinks it would look better.”

He took down the name and address, which was in Hollywood, a good many miles away, and hung up. Then he looked anxiously at his watch.

If only Jupe would hurry back. They had located Octavian — but if they didn’t act fast they’d lose him again!

PETE LED THE WAY as, puffing slightly, the three boys pushed their bikes up a small rise and out into the open part of Dial Canyon.

The canyon was narrow and quite high up in the hills north-west of Hollywood. Only one road led to it, an unpaved one that ended in this flat section. Here, the late Horatio August’s house sat in a large area of long, untended grass.

It had been Jupiter’s idea to visit the house. He didn’t know exactly what they were looking for, but he thought they should see the house where Gus’s great-uncle had lived.

It had taken them longer than they expected to ride through the hills. Now it was nearly noon, and the sun was high and hot overhead. They paused to wipe the sweat off their faces and to look at the empty home of Horatio August.

Three storeys tall, of timber and plaster, it was very impressive standing all by itself in the open. Nothing moved and there was no sign of life. They rode up to the front door and left their bicycles on the grass.

“We haven’t got the key, but there ought to be some way to get in,” Pete said. “After all, we have permission from Mr. Dwiggins.”

“We could break a window to obtain entrance,” Gus suggested.

“We don’t want to do any damage if we can help it,” Jupiter answered, “even though the house is soon going to be torn down. I have a bunch of keys with me — ” He hauled from his pocket a fat bunch of keys which had accumulated at the salvage yard over a period of years. “Let’s see if one of these will open the door, before we try anything else.”

They walked up three steps to the front door and Pete tried the knob. To his surprise the door swung open silently.

“It’s open already!” he said. “It wasn’t even latched.”

“That’s odd,” Jupiter said, frowning.

“Perhaps Mr. Dwiggins left it open after he was here the other day,” Pete suggested. “Or maybe someone else did. It doesn’t matter — people don’t worry much about locking up empty houses.”

They walked into a dark hallway. On either side were two big rooms, dusty and empty, except for some scraps of paper on the floor.

Jupiter entered the one which he deduced had been the living-room. He looked around, but there didn’t seem to be anything much to see. There was no furniture. The room was panelled in dark walnut, which still shone despite a layer of dust.

There was nothing to see, so he turned and strolled across the hall into the opposite room. This one had apparently been a library, because built-in bookshelves towered round three sides of the room. Now they were empty of everything but dust. Jupiter stood in the middle of the room, looking at the shelves. “Ah!” he said, after a long look.

“What do you mean, ah?” Pete asked. “I can’t see anything to ah at.”

“You must train your powers of observation if you’re ever going to be a first-rate investigator,” Jupe said. “Observe that section of bookcase directly in front of me.”

Pete stared at it. “I don’t see anything but dust,” he said at last.

“At the end,” Jupiter told him, “it extends outwards beyond the next section by a quarter of an inch. I consider that very significant.”

He walked over and tugged at the section of bookcase. Slowly it swung open. Behind it was the black opening of a narrow door.

“A secret room behind the bookcases!” Jupe said. “The bookcase door was not quite shut.”

“Wow!” Pete exclaimed. “We’ve found something.”

“We should have brought flashlights,” Jupiter said. “That was careless of me. Pete, go out and get the electric headlight off your bicycle.”

In a moment Pete was back and handed Jupe the bicycle headlamp.

“I guess you’ll want to go first,” he said.

“There can’t be anything alarming in there,” Jupiter said. “Not in a house empty this long.”

Pete wasn’t so sure. They had encountered a couple of secret rooms before in their investigations, and one of them had held a skeleton. But Jupe turned on the bright beam and marched into the tiny room behind the bookcase, and Pete and Gus followed.

They took no more than three steps and stopped.

There was no skeleton in this room, nor anything else. It was completely empty. Shelves on the wall suggested that books had once been kept in this room, but they were gone.

“Nothing,” Pete said in disappointment.

“Nothing?” Jupe asked and Pete looked around again.

“I don’t see anything,” he said.

“Because you’re looking for the wrong thing,” Jupe said. “What you’re looking at is so commonplace, so ordinary, that your mind doesn’t realize how extraordinary it really is.”

Pete blinked again. He still didn’t see anything.

“All right, tell me,” he said. “What’s so unusual I can’t see it?”

“He means there’s a door,” Gus said. Pete saw it now — an ordinary doorknob, and the crack around a door set into the wall. It wasn’t meant to be hidden. He just hadn’t noticed the doorknob because every room has a door, and seeing one in here hadn’t registered on him.

Jupiter was already turning the knob. The narrow door opened easily and by the beam of the light they could see wooden steps slanting downwards.

“It looks as if the steps go down to the cellar,” Jupiter said. “We might as well try them and see where we come out.”

“Leave all the doors open then,” Pete urged. “I don’t want any closed doors behind me.”

Jupiter marched down the stairs, the others behind him. The walls on either side were so close they brushed their shoulders against the wood.

At the bottom Jupiter stopped. Another narrow door barred their way. It opened easily towards them. They stepped through into a small, stone-walled room where the air was cool and damp.

“We’re in a cellar,” Jupiter said, flashing the light round. They saw many curious slanting shelves which meant nothing to either Pete or Jupiter. However, Gus recognized their function.

“This is a wine cellar,” he said. “Those shelves are for laying out the bottles of wine. Look, there’s a broken bottle in one. This was Great-Uncle Horatio’s private wine cellar.”

Jupiter suddenly froze. He switched off the light and darkness enveloped them.

“What is it, Jupe?” Pete dropped his voice to a whisper.

“Sssh! Someone’s coming. Look!”

Beyond the open door which led into the rest of the basement appeared a beam of light. Low voices could be heard.