ghing 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.

"No, nothing of value. The owner has a very bad name. No doubt he is
receiving stolen goods, but it is always hard to prove anything."

Penny relapsed into a thoughtful silence which she presently ended by
saying:

"You know, Dad, a peculiar thing happened yesterday. I don't suppose
it could have the slightest connection with the case and yet it set me
to thinking."

"What was that?" Mr. Nichols asked smilingly.

"I saw George Brunner talking with Jerry Barrows in his office."

"That young protege of yours?"

"He isn't any longer," Penny retorted. "I realize now that I was
deceived by his story. But why should he be working for Mr. Brunner?"

"That can be explained easily. I suppose Brunner didn't take the
trouble to check up his record."

"He was threatening the boy," Penny reported, her eyebrows puckering
into a frown. "I distinctly heard him say: 'You'll do as I tell you
or--' Then he saw me and broke off."

"You're certain that was what he said?"

"Of course I am! You don't think I imagined it, I hope!"

"No," Mr. Nichols laughed, "but one's ears often distort conversation.
It does seem a little odd that Brunner should have any connection with
this boy. Still, there must be a logical explanation. Brunner's
reputation is above reproach, you know."

"I don't think he's so very honest," Penny declared. "After the way he
acted about Susan's car I wouldn't trust him an inch."

"Brunner does make glib promises," the detective admitted. "In