"Tire tracks, eh! There's been an automobile in here," he muttered to himself. "I wonder how on earth a car could get this far into the woods!" Then he remembered his father's remarks on the value of developing his powers of observation, so he went over closer and examined the marks in the mud. "That's a strange tread," he thought. "I've never seen a tire mark quite like that before." He gazed at it until he was sure that if he ever saw a similar auto tread again he would recognize it. "That just goes to prove that dad was right," said Joe. "Probably I've seen auto tires like that often, but I've never noticed the markings, and now that I do notice one in particular it seems strange to me. But I wonder what an automobile was doing in here and how it came to get here in the first place!" However, he gave the matter little further thought and retraced his steps through the woods until he returned to the other boys, who were getting dressed after their swim. "I thought automobiles weren't allowed in Willow Grove," he said casually to Chet Morton. "Neither they are. You have to park just inside the fence." "Well, somebody brought a car right down into the grove." "They couldn't. There's no road." "Well, there's a sort of clearing over there," said Joe, motioning in the direction from which he had just returned. "It looks as if it had been a road at one time." "That's probably the old creek road. It hasn't been used for years." "Well, it was used just this week. I saw the marks of an automobile tire over there not ten minutes ago. And it was a mighty peculiar tread, too. Like this--," and Joe commenced to draw a replica of the design in the sand, using a thin stick of wood as a pencil. Chet Morton stared. "Why," he exclaimed, "there's only one car in the city has tires like that!" "Whose car?" "Mine!" exclaimed Chet, springing to his feet. "Where _is_ this road you found?" Joe Hardy quickly led the way and all the other boys came trooping along behind, the whole band thrown into a state of great excitement by this unexpected discovery. They all knew that Chet's car was of an unusual make and that the tires were distinctive. When they reached the clearing and Chet had examined the imprint in the mud he exclaimed: "There's no mistake about it! My car has been here! No other car in the city has a tread like that!" "Perhaps the car is still around here," suggested Frank quickly. "For all we can tell, the thief may have abandoned it and picked this road as a good place to hide it." "It would be an ideal place," agreed Chet. "This road leads off the main highway, and it isn't often used. Let's take a look around, anyway." The boys quickly scattered, some taking one side of the road, the rest taking the other. For a while the search continued without success, but at last Frank and Chet, who were following the abandoned road farther down, gave a simultaneous cry. "Here's a bypath!"