While Jack was out on the river practicing for the approaching compet.i.tion, Penny accompanied her father to the mainland to mail letters and make a few purchases Mrs. Gandiss had requested. In returning to the waterfront, they wandered down a street within view of the Gandiss factory.

Penny's attention was drawn to a man who came out of an alley at the rear of the plant and stood staring at a tiny junk shop which was situated directly opposite the Gandiss factory.

"There's Joe the Sweeper," she observed aloud. And then an instant later added: "That's queer!"

"What is?" inquired her father.

"Why, that junk shop! I've been down this street several times, but I never noticed it there before. I would have sworn that the building was empty."

Mr. Parker gave her a quick, amused look. "It was until yesterday," he informed.

"You seem to know all about it!" Penny suddenly became suspicious. "What are you keeping from me?"

Mr. Parker did not reply, for he was watching the man who had emerged from the alley. Joe seemed to debate for awhile, then crossed the street and entered the junk shop.

"Good!" exclaimed Mr. Parker. "Our bait seems to be working."

"What are you talking about?" Penny demanded in exasperation. "Will you kindly explain?"

"You recall Mr. Gandiss asked me to help him solve the mystery of those bra.s.s thefts at the plant."

"Why, yes, but I didn't know you had begun to do anything about it."

"Our plan may not succeed. However, we're trying out a little idea of mine."

"Does it have anything to do with that junk shop?"

"Yes, the place was opened yesterday by Heiney Growski."

Penny's blue eyes opened wide for she knew the man well. A prominent detective in Riverview, he had won distinction by solving a number of difficult cases.

"Heiney is an expert at make-up and impersonation," Mr. Parker added. "We brought him here and installed him as the owner of the junk store across the street. His instructions are to buy bra.s.s and copper at above the prevailing market prices."

"You expect employes who may be pilfering metals to seek the highest price obtainable!"

"That's our idea. It may not work."

"It should," Penny cried jubilantly. "Sweeper Joe went in there not three minutes ago! I've suspected him from the first!"

"Aren't you jumping to pretty fast conclusions?"

"From what I heard him say to the gatekeeper Clayton, I'm sure he's mixed up in some underhanded scheme."

"You're not certain of it, Penny. Joe has been carefully investigated. He seems too stupid a fellow to have engineered such a clever, organized method of pilfering."

"He never appeared stupid to me. Dad, let's drift over to the junk shop, and learn what is happening."

"And give everything away? No, Heiney will report if anything of consequence develops. In the meantime, we must show no interest in the shop."

To Penny's disappointment, her father refused to remain longer in the vicinity of the factory. Without glancing toward the junk shop, they walked on to the riverfront. The motorboat they had expected to meet them had not yet arrived. While Mr. Parker purchased a newspaper and sat down on the dock to read, Penny sauntered along the sh.o.r.e.

A short distance away on a stretch of beach, a boat had been overturned.

Sally Barker, in blue overalls rolled to the knees, was painting it with deft, sure strokes. Penny walked over to watch the work.

Glancing up, Sally smiled, but did not speak. A smudge of blue paint stained her cheek. She had sanded the bottom of the _Cat's Paw_, and now was slapping on a final coat of paint.

"Will it dry in time for the race tomorrow?" Penny inquired, making conversation.

"The finish won't be hard, but that's the way I want it," Sally said, dipping her brush. "It makes a faster racing bottom."

"Then you're all ready for compet.i.tion?"

"The boat is ready." Sally hesitated, then added. "But I may not enter the race after all."

"Not enter? Why?"

Having finished painting, Sally carefully cleaned her brush, and tightly closed the paint and varnish cans. She wiped her hands on her faded overalls.

"The boy who was racing with me served notice this morning that he had changed his mind. I haven't asked anyone else, because I didn't want to be turned down."

"But I should think anyone who likes to sail would be crazy for the chance--" Penny began. Then as she met Sally's gaze, her voice trailed off.

"You know what I mean," said Sally quietly.

"Not the factory episode?"

"Yes, word traveled around."

"Jack didn't tell?"

"I don't think so, but I don't know," Sally replied honestly. "Anyway, everyone learned why I was discharged. Pop is furious."

"Your mother too, I suppose?"

"I have no mother. She died when I was ten. Since then, Pop and I have lived aboard the _Queen_. Pop always taught me to speak my mind, never to be afraid, and above all to be honest. To be accused of something one didn't do and to be branded as a thief is the limit!"

Penny nodded sympathetically. "About the race," she said, reverting to the previous subject, "you aren't really serious about not entering?"

"It means everything to me," Sally admitted soberly. "But I can't race alone. The rules call for two persons in each boat."

"You need an expert sailor?"

"Not necessarily. Of course, the person would have to know how to handle ropes and carry out orders. Also, not lose his head in an emergency. To balance the _Cat's Paw_ right I need someone about my own weight."

"It has to be a boy?"

"Mercy, no! I would prefer a girl if I knew whom to ask." Sally suddenly caught the drift of Penny's conversation, and a look of amazed delight came upon her face. "Not you!" she exclaimed. "You don't mean you would be willing--"