They all watched the humming signal and wondered if Pete would see the call for help.

Where Pete sat up in the beams of the old roller coaster, the sharp wind from the mountains made him shiver. He could barely see the exits from the carnival in the early dusk of the gloomy day.

None of the people he had seen leave had come back, and the carnival would open in not much more than an hour. Where were the carnival people he had watched leave, and where were Jupiter, Bob and Andy? Andy was supposed to be in his booth before the carnival opened, and it wasn’t like Jupiter or Bob to stay away so long without at least trying to send a message. Pete was worried. Sometimes, Jupiter’s tendency to keep his plans secret so that he could astound them all, annoyed Pete. It was, he knew, only the First Investigator’s love of the dramatic, but it had got the boys into tight corners before. He hated to leave his post, but he was uneasy now.

He climbed down from the roller coaster and hurried through the dilapidated amusement park. The enormous, laughing mouth of the Fun House seemed to leer at him as he passed it and went on to slip back through the hole in the fence.

At the carnival the Ferris wheel gondolas were being uncovered. The carousel was already playing its gay music. Andy Carson was not at his booth. Pete chewed on his lower lip. Where were they? He suspected that Jupiter had taken them to the man who wanted to buy crooked cats, but where was that? Some sixth sense told Pete that something was wrong.

If they came back to the carnival, they would expect to find him at his post. They would, perhaps, want his report at once. If he left his post and went looking for them, he could miss them, and they could return to the carnival to find him gone. On the other hand, if they needed help, he — Pete remembered the new directional-and-emergency signal!

He dug into his pocket and brought out the tiny instrument. He stared at it eagerly. But it was silent. The red emergency light was dark.

In the locked storeroom of the small house, Andy looked up at Jupiter from the floor.

“How far does that signal reach, Jupe?”

“Three miles,” Jupiter said, and suddenly groaned again. “Of course, the carnival is almost five miles from here! Pete won’t get our signal!”

They all looked at each other.

“Someone’ll hear us yelling, fellows,” Bob said, trying to make his voice optimistic.

“Of course they will,” Jupiter said firmly. “But in the meantime, we can try to find a way out ourselves. The experts say there’s no such thing as a room you can’t get out of somehow. There’s always a flaw in a room. Come on, let’s find it.”

“But how, Jupe?” Andy asked. “We’ve looked.”

“There’s always a chance that we’ve missed something,” Jupiter declared. “Bob, you examine all the walls for weak spots, places where pipes go through, anything. I’ll check the window more closely, and Andy can recheck the doors and that cupboard in the corner.” Despite their pessimism, Andy and Bob couldn’t help being convinced by Jupiter’s staunch refusal to give up. They set to work with renewed vigour. But Andy soon decided once again that there was no way. out through the solid doors, and Bob found no weak places in any of the walls.

“Keep trying, fellows!” Jupiter urged. “There must be some weakness in this room.”

The First Investigator continued to study the barred window, and from time to time yelled out for help. Bob got down on his hands and knees to examine the walls at the floor. Andy went into the single cupboard. “Jupe! Bob! Look here!”

The carnival boy held a typewritten sheet of paper he had found in the cupboard. “It’s a complete itinerary of the carnival,” Andy told them. “Our whole route and schedule in California.”

“Then the tattooed man is part of the carnival” Jupiter said in triumph.

“Or at least he’s following the carnival pretty closely,” Bob said.

“Andy,” Jupiter exclaimed, “did you recognize his voice? You didn’t recognize the tattoo, or his face, but think about his voice”

“No,” Andy said slowly, “I’m sure I’ve never heard that voice before, Jupiter.”

Jupiter thought a minute. “He could be disguising his voice, too. It had that odd rasp.”

After looking at the carnival itinerary, Bob began to rummage round in the long, narrow cupboard that was partly filled with old boards and boxes. Suddenly he came out with some strange clothes in his hands.

“Look at this, fellows. I found it all just dropped on the floor.”

Bob held up a pair of strange, black overalls that were cut very narrow, like tights; a black hoodlike head covering that fitted a whole head but left the face open; and a pair of black canvas shoes with odd rubber soles that looked a little like curved suction cups.

Jupiter frowned. “It looks like some kind of costume, Records. Perhaps a carnival costume, but I don’t recall any costume like that. Andy?”

Andy was staring at the black garments with a puzzled expression. He took them and studied them. “Well, what is it, Andy?” Jupiter wanted to know. Andy shook his head.

“None of our people wears a costume like this, but — ” The carnival boy hesitated, shook his head. “I can’t be sure, fellows, but I think this looks a lot like a costume the Amazing Gabbo used to wear.”

“The Amazing who?” Bob said, staring.

“Gabbo,” Andy said. “When I was just a little kid, right after my Mom died but before I went to Grandma, my Dad worked a little while with a small circus near Chicago. The Amazing Gabbo worked in the show, too, for a few days. We never, knew him, really, and he wasn’t around long. I only remember him because he was caught stealing from the circus and fired. I think he got into worse trouble later and went to prison.”

“Prison?” Jupiter said quickly. “Then he could be a thief! Did he look like that tattooed man, Andy?”

“I don’t know, Jupe. I guess his age is about right. But I wouldn’t remember what he looked like. I don’t think Dad would, either. I mean not right away unless someone told him to look for Gabbo. I guess we really never saw him out of his costume.”

“And this looks like his costume?” Jupiter asked.

Andy nodded. “It sure does, I think. And those shoes are a special kind used by human flies in their acts. You know, so they can climb almost any wall.”

Jupiter gaped. “A human fly?”

“Sure,” Andy said. “That was Gabbo’s act. He — ”

But Jupiter was no longer listening. “That old man who tried to grab your crooked cat last night! He got out of that dead-end area. The only way out was to climb that high fence. No one could climb a fence like that — excepts maybe, a trained human fly!”

“And Gabbo would know how to handle a lion!” Andy said.

“But, fellows,” Bob said, “Andy already told us he doesn’t know the tattooed man.”

“The tattooed man could be another disguise, Records,” Jupiter pointed out. “We must get out of here! If he gets to the fifth cat and escapes, we may never find him! Yell, fellows!”

They began to yell at the window again. But their voices echoed without response.

Pete coasted into the salvage yard on his bicycle. He had made his decision some half an hour ago — he would look for the other boys.

But as he rode into the yard in the gathering dusk, all he saw was Konrad taking the last of a load off the small truck. “Have you seen Bob or Jupiter, Konrad?” Pete cried out to the big Bavarian helper of Uncle Titus Jones.

“I don’t think I see them for a long time today, Pete,” Konrad replied stolidly. “There is something wrong?”

“I — don’t know, I — ”

Konrad raised a massive hand. “Wait, Pete. What is that strange noise? I think it is close around somewhere.”

The big Bavarian looked all around him, perplexed Pete listened and heard the strange, muffled sound — a steady, low beeeeeeeeeeeeeeeeeeeeep It seemed to come from somewhere close to his pocket!