"As usual we failed to make a capture," the detective acknowledged gloomily. "The police bottled up all the main highways leading from the city. All suspicious trucks were searched. We thought certain we'd catch Molberg with the goods, but he was just a little too smart for us again."

"Were many wheels stolen last night?" Penny inquired curiously.

"A good truck load at least. This case has begun to make me look like an amateur. If I don't begin to close in on the Molberg gang soon I'll be the laughing stock of the city."

"You'll solve the case," Penny smiled confidently.

"I'm not so sure of that. You see, while Molberg is a daring crook, the evidence indicates that he is merely a go-between for a far more clever criminal. A master mind plans out every move that the gang makes, yet doubtlessly that person has never been under suspicion. Such a man always takes care to keep within the law himself although he engineers the most daring crimes by means of his henchmen."

"And of course they take all the risk."

"Yes, if his gang is broken up, he merely organizes another."

"Have you no clue as to where this so called 'master mind' may be?"

"None whatsoever. He has kept his hand well hidden. We have made a few arrests but the men can't be made to talk. It may be that they aren't even aware of his identity."

"I don't suppose you've ever been able to get any evidence against that place where Susan bought the stolen wheel," Penny ventured.