“Exactly, and that’s why it’s so important to watch.” Suddenly, from across the hot and sunny street, there came a muffled shout.

“Hello! Someone! Hello out there!”

The cry was faint but clear in the stillness of the hot afternoon.

“Hey, out there! Help!”

Pete whispered, “It’s from the League house. At the back.”

“Maybe Mr. Harris is locked in,” Bob said. “Maybe the thieves attacked him again.”

The boys hesitated. If the dark men were around, they might get into trouble if they showed themselves. But if Mr. Harris was locked in, they ought to try to help him.

“What’ll we do?” Pete asked.

“1 guess we had better take a look, but let’s be careful, Pete. If we see anything of those men we better get away fast.”

They crossed the empty street warily. Since they knew the front door was locked, they went cautiously around to the rear of the house and tried the back door.

“It’s open,” Pete whispered, as he turned the knob. He pushed the door open, and they walked along a dark hallway until they came to what had been the kitchen of the old house. It was empty now. They went through a swinging door into the rear of the cluttered entry hall. In the dim, cool hall they listened.

“I don’t hear anything,” Bob whispered.

“But I know that call came from somewhere in here,” Pete insisted. “Let’s try the office.”

They opened the office door carefully, but the room was silent and empty. Bob pointed to a cupboard door. The two boys tiptoed over to it and listened for a minute. There was no sound. Gingerly, Bob opened the door while Pete stood to one side, holding a heavy paperweight from Mr. Harris’s desk.

The cupboard was empty.

“That shout had to come from somewhere,” Pete said. “Maybe he’s shut in where there isn’t enough air, and he’s collapsed,” Bob suggested.

“Gosh, that could be,” Pete agreed. “We’d better hurry and look everywhere.”

Quickly they searched all the rooms downstairs. Finding nothing, they went up to the first floor. There they looked into a large meeting room that had been made from three smaller rooms. It had a platform at one end. Obviously this was the place where Mr. Harris had been attacked during his lecture.

“Hello! Hello! I hear you! Help!” The cry came again, from overhead.

Bob exclaimed, “He must be on the second floor!”

“Come on!” Pete cried, already running for the stairs. There was little light on the second floor. The windows were shuttered, and dust lay thick on a pile of planks strewn about the floor. The doors to all the rooms along the dark corridor were open. The boys stood there, listening intently.

Suddenly there was a frantic banging at the far end of the corridor. Pete picked up a large plank, and together they walked down the hall. The room at the end of the corridor was bare and completely empty. They stood there for a moment, waiting for another shout or a bang. Then Bob noticed the door on the far side of the room.

“There, Pete!”

Pete nodded, and the two boys approached the closed door. Bob tried the knob, while Pete stood ready with his plank.

“It’s locked,” Bob said. “Can we break it down?”

Behind them the door to the corridor slammed shut. They whirled, their eyes wide and startled. Pete held his plank ready to repel any attack. But no one was there. Only the closed door.

“Pete!” Bob cried.

The lock on the room door clicked from outside, and a familiar voice roared with laughter beyond the locked door.

“Boy, are you smart guys ever dumb!” the laughing voice sneered. The voice of Skinny Norris!

Bob and Pete rushed to the door, but it was tightly locked. Although Pete tugged and pulled and raged, he couldn’t budge it.

“Skinny Norris, you let us out of here!” Bob yelled.

“If you don’t,” Pete threatened, “we’ll fix you when we get out of here. We’ll — ”

“But you won’t get out.” Skinny taunted them through the door. “I’m just going to let the two of you stew in there. Serve you nosey brats right. Too bad Fatso Jones isn’t with you. I’d like to see that fat smart Aleck trying to get out of there.”

“You wouldn’t talk like that if Jupiter was here,” Bob said angrily.

“You shut up, Bob Andrews!” Skinny shouted. The envious Skinny hated to have anyone suggest that he wasn’t a match for Jupiter. “You’re in bad trouble, you hear?”

“You’re the one who’s going to be in trouble,” Pete said. “What do you think you’re doing anyway?”

“What am I doing?” Skinny snickered out in the corridor. “Why, I’m protecting private property, that’s what I’m doing! I heard noises in here when I was passing by. I came in, and guess what? I caught two trespassers cold.”

“You’re crazy, Skinny! No one’ll believe you.”

“No? The front door was locked and no one was here. Just what were you doing coming in the back way?” Skinny laughed nastily. “I’ve been watching that junkyard of Fatso’s uncle ever since Ted Sandow asked about you. I knew I’d catch you at something.”

Bob groaned. “Skinny, Mr. Harris knows we’re here. We’re working for Miss Sandow.”

“Don’t try to fool me,” Skinny said from the corridor. “Ted Sandow told me he was looking for a valuable statuette, and I could tell he thought you three had stolen it.”

“Oh, no!” Pete cried. “That was before we talked to Ted. He’s the one who hired us to find the statuette. Why don’t you stop trying to be smarter than Jupiter?”

“I am smarter than that fat show-off! You can just sweat it out in there. If Fatso Jones is so smart let him rescue you. I’m taking off. So long, wise guys!”

Bob looked despairingly at Pete, then walked over to the locked door. He could hear Skinny going downstairs. After a long time, they heard the back door slam.

Bob and Pete looked at each other hopelessly as Bob moved away from the door. They were obviously in a bad spot.

“The windows are barred,” Pete said, “and that other door is locked, solid.”

“It’s an old house,” Bob suggested. “How about the walls or the floor? Maybe we can find a weak spot — a loose board or something.”

Pete wasn’t optimistic, but he inspected the floor while Bob studied the walls. Unfortunately there were no weak spots in the floor.

“The walls are solid as a rock, too,” Bob said glumly. “Maybe Jupiter or Mr. Harris will come soon,” Pete suggested.

“Our bikes are still in that alley, Jupe’d see them.”

“Sure,” Pete agreed, “he’d know we were in here somewhere.”

The boys grinned at each other, but the grins were feeble. Each was aware of the fact that he was trying to convince the other that Jupiter would somehow come to their rescue.

“Maybe,” Bob said weakly, “Mr. Harris will come back.”

“And maybe he won’t, or not for a long time. Maybe he won’t come back until tomorrow.”

“There has to be some way out!” Bob insisted.

They looked all round the small room again without much real hope. They were stuck, and they knew it. Trapped by that stupid Skinny Norris.

“Bob!” Pete cried, staring at something behind his fellow investigator. “The door! It opens inwards. The hinges are right there inside.”

“We can push out the hinge pins!”

“Sure, it’ll be easy. Boy, is that Skinny dumb.”

“But we don’t have any tools,” Bob said.

“Oh, yes, we do.” Pete pulled out his heavy scout knife with its many strong blades and quickly went to work. The hinge pins were covered with old paint, and were very stiff. Pete began to sweat as he struggled to loosen them.

Bob stood anxiously beside him, trying to help as much as he could.

Finally, the last hinge pin fell into Pete’s hand. Bob grasped the upper hinge, and Pete grabbed the lower. They counted to three and pulled. The door swung inwards, broke free of the lock, and fell to the floor with a loud crash.