“THERE should be a certificate of title somewhere,” said Joe Lewis, as he peered inside the parked automobile. “Or if there isn’t, maybe there’s a letter or something else that has his name and address on it.”

“Here’s a driver’s license,” announced Bob, who had reached into the pocket of the door. “Issued to Harry Walker, and the address is rural route. Let’s see the description. Height, five feet-eight; weight, one hundred-forty; eyes, brown; hair, black; age, fifty-one.”

“That’s the thief, all right,” said Joe conclusively. “It fits him to a T.”

“But the name,” argued Bob. “How do you figure that out? The fellow we think is the thief gave his name as Henry Overton, while this driver’s license has the name Harry Walker.”

“Maybe that was only an alias, or false name,” suggested Joe. “He could easily have changed that. But what do we do now, Bob?”

“More than I know. What do you suggest?”

“Suppose we go back in Jordan’s house and see our dads. We’ll have to hurry, though, or this thief will beat us to it.”

“To what?”

“As I was saying,” resumed Joe, “we’ll go back and get our dads, and the four of us can go out to this thief’s house and be there when he gets there.”

“Then what?”

“Easy enough. We’ll arrest him and make him get the stolen specimens.”

“But can we do it?” demanded Bob. “Will we be allowed to?”

“Sure. We’ve got the goods on him, haven’t we? We know that the specimens that Mr. Jordan read off are the stolen ones, don’t we?”

“All right. Lead the way.”

As quickly as they could, Bob and Joe went back in the house through a rear entrance. Then quietly they found the room in which Mr. Holton and Mr. Lewis were hiding.

The boys found their fathers waiting anxiously. The frown on their faces gave way to a smile as they caught sight of their sons.

“What did you find?” inquired Joe’s father.

Bob told of their desire to drive to the thief’s residence before the man could himself do so.

“I’m willing,” said Mr. Lewis, who was more than anxious to recover the stolen specimens. “While on our way we’ll stop at a police station and pick up an officer. I’d sort of hate to carry out your plan without doing that.”

Before leaving the house, Mr. Holton instructed the butler to inform Mr. Jordan of where they had gone. Then, with his son and friends, he hurried out to his car.

Mr. Lewis knew exactly where to find the residence of the thief, or at least the address that was on the driver’s license.

“It is several miles from here, but we’ll probably have a good start ahead of the thief,” Joe’s father said, as the automobile was driven out into a main traffic artery.

Before the four left the city limits, they stopped at a police station and secured the services of an officer. Now, with the protection of the law, they felt safe to continue the venture.

A half hour’s ride over a narrow country road brought them to a large house set back in a wide lawn.

“This must be the place,” observed Mr. Holton, bringing the car to a standstill. “I wonder if anyone is at home?”

“Better not leave the machine here,” warned the policeman. “If the guy we’re after should see it, he probably would not show up for us to catch him. Drive it farther toward the house, out of sight of the road.”

“Glad you reminded me,” Mr. Holton said, and drove still farther on.

All stepped out and made their way over the wide lawn. As a precaution against possible danger, the officer kept a ready hand on his revolver.

“You can’t tell who might be there to bump us off,” he said, his eyes on the house. “There could be several more outlaws waiting there.”

They reached the dwelling safely, however, and then knocked on the heavy door.

But either no one was there, or else they refused to admit the strangers, for the door did not open.

“No use keeping this up longer,” said the policeman. “We’d better hide around the side of the house and wait for the fellow we’re after. Feel sure he’ll come here?”

“We don’t know,” returned Bob. “This may not even be where he lives. He might have stolen the car he had from someone who does live here.”

They took places beside the house, at a point where they could command a good view of the road and driveway. How long it would be before the thief would show up, if at all, they had not the slightest idea. They hoped, however, it would not be long, for darkness was not far off.

Hardly five minutes had passed when Bob caught the arm of the policeman, who was nearest him.

“Listen!” the youth hissed. “There’s a car coming. Hear it?”

Sure enough, the faint sound of an approaching automobile was breaking the evening silence. Whether the vehicle was that of the thief, the hiding forms did not know. Their hopes were high, though, as the purring became louder.

Those hopes were not shattered, for a minute later the same car that had been parked in front of Mr. Jordan’s estate turned in the driveway.

“Look!” breathed Joe. “It’s the man we’re after, all right. He’s stopping. Sees our car and wonders why it’s here, I guess.”

At word from the policeman, the four stepped out and advanced toward the man. As they went nearer, the officer displayed his revolver.

“You’re under arrest,” he said. “Throw up your hands and tell us where you put those stolen goods.”

The man raised his arms and moved toward them. But he refused to further comply with the command.

“You are wrong—entirely wrong in your thinking,” he said in a crafty voice, a faint smile coming over his face. “You have made a terrible mistake and picked out one who is innocent. I know nothing about any stolen goods.”

“None of your monkey business,” snapped the policeman, advancing toward the man. “We’ve proof of your guilt and want the stuff you stole. Now, get it and get it fast, or I’ll be tempted to pass a .45 through your ribs!”

“But I say,” persisted the alleged thief, raising his voice to a high-pitched drawl, “I know nothing about what you are talking.”

Bob advanced toward him.

“What about those specimens you offered to sell to Mr. Jordan?” the youth demanded, never taking his eyes from the fellow. “Just where did you get them? It didn’t happen that you stole them out of a museum truck, did it?”

“Why, you——I’ll knock you over that fence!”

He moved toward Bob, but soon decided not to carry out his threat.

The policeman became even more impatient.

“Did you hear what I said?” he snapped, prodding the man with his revolver. “We want that stuff you stole, and we want it right now. You’d better talk!”

Much to the surprise of all, the man no longer denied his guilt. Instead, he motioned them to follow him up to the house. Whether he had been frightened by the officer’s terse command, or intended to resort to some means of escape, they did not know.

He produced a large bunch of keys and opened the heavy door, at the same time beckoning for his unwelcome visitors to follow.

“I’ll take those keys!” The policeman held out a hand.

The accused man hesitated a moment, then handed them over.

“What you want is in the basement,” he said, as he led the way through the large room. “I will get it for you, never fear.”

When almost at the rear of the house, he stopped and opened a narrow door. Then, switching on a light, he went down a steep flight of stairs, the others at his heels.

They were in the basement, threading their way between rows of boxes, when something unexpected happened. The light suddenly went off, leaving them in total darkness. The eyes of the pursuers, unaccustomed to the blackness, could make out nothing around them. It had happened so quickly that there was a short period of fumbling about.

Bob Holton felt a form brush past him rapidly, as if in wild haste.

The youth’s fist shot out and caught the form squarely with such force that he fell at once with a groan.

“I got him!” Bob cried. “Now to switch on the light.”

During the next few minutes there was a wild scramble in an attempt to find the concealed switch. At last, when it became apparent that it could not be found, Joe bent his efforts on finding the stairway, at the head of which Joe knew there was a switch.

A thrill of hope passed through him as he felt his foot touch the top step. Now there would be light, the youth thought.

Meanwhile, the others were still vainly searching for the concealed switch.

“I give it up,” sighed Mr. Holton, straightening out hopelessly. “Our only chance now is to find the switch at the head of the stairs.”

The words were barely out of his mouth when suddenly the light came on.

Bob uttered a wild cry of surprise.

“For the love of Pete!” he exclaimed. “I’ve knocked out the policeman!”