Penny would have carried the argument further, but Susan tugged at her sleeve. They hastily left the shop. As they drove away, they saw the dealer standing at the plate glass window, watching. "Such a horrible man!" Susan gasped. "I was actually afraid of him. What made him act like that?" "I think he must have guessed why we came," Penny told her. "As a sleuth I seem to be a walking advertisement of my calling!" "He recognized you the minute you stepped into the store. Didn't that strike you as queer?" "Yes, it did, Susan. I'm almost certain that man is dealing in stolen tires. He's probably afraid of the law. It's to his advantage to recognize plain clothesmen and persons who might cause him trouble, I imagine I've been seen with my father." "I should think the police could arrest him." "It isn't as easy as one might believe, Susan. If a fence is caught with stolen merchandise he claims to have purchased it in good faith. Actually he has taken it off the hands of some thief. An arrest is hard to make." "Then there's nothing we can do?" "I don't know. I'll ask Father when he comes home tonight." "I think a fence is even more contemptible than a thief," Susan said scornfully. "I'd give anything if I hadn't bought that tire." "I'm glad you did," Penny smiled, "for the clue we gained may prove useful to Father." The girls were relieved when they reached the end of South Lake and turned into a more pleasant street. Driving toward their homes they relapsed into a long silence, each absorbed in her own thoughts. There were occasions when the two friends talked frantically for hours. There were other times when they would speak scarcely a word, yet enjoy perfect understanding. Penny had slumped in her seat. Suddenly, she straightened, her eyes riveted upon a pedestrian who was crossing the street in front of the coupé. "Susan, isn't that Jerry Barrows?" she demanded excitedly. The car swerved wildly as Susan turned to look. "It is!" she exclaimed. "Stop the car," Penny pleaded. "I want to talk with him." Susan brought the coupé to a halt at the curbing. Penny sprang out. "Jerry Barrows!" she called. The boy wheeled and saw her. He hesitated an instant, then turned and ran. CHAPTER IX A Trap "Wait! I want to talk with you!" Penny called. The boy paid no heed. As she ran after him he darted into the nearest alley. Provoked, Penny hastened back to the car where Susan was waiting. "Let's try to catch him," she proposed, springing in beside her chum. Susan turned the coupé in the narrow street and drove into the alley. They could see the boy only a short distance ahead. "We'll overtake him," Penny cried jubilantly. Aware that he was being pursued, the boy ran faster. Then noticing an opening between two buildings, he squeezed through it and was lost to view. Penny tried to follow afoot but soon gave it up. She returned to the coupé disheartened.