When they reached the crossroads Chet had not yet appeared, so they rested in the shade of the trees until at length the chubby youth came panting along the road, his lunch under his arm. "If I only had my roadster I wouldn't be late," he said, as he came up to them. "I've been so used to it that I've forgotten how long it takes to walk this far." "Well, are we all set?" asked Frank. "Everybody's here. Where are we going?" "What do you say to Willow Grove?" "All those in favor say 'Aye'," demanded Chet, and there was a chorus of "Aye" from the crowd. "It's unanimous," Chet decided. "Willow Grove it shall be. Let's go." Willow Grove was about a mile farther on. It was some distance in from the road, and was on the banks of Willow River, from which it got its name. It was an ideal place for a picnic, and as it was somewhat early in the season it was hardly likely that other parties from the city would be in the grove that day. Frank told the other boys about Chet's adventure with the auto horn and the story was greeted with shouts of laughter, which were redoubled when Chet told how he had later jumped down from the wagon and run along behind, shouting to Lem Billers to give him a ride. "It was a shame!" he confessed. "The poor old chap reined in his horses and made me come up and sit on the seat beside him. He asked me if I had walked very far and then he told me all about his argument with the policeman and the chauffeur. I could hardly keep my face straight." When the boys reached the lane that led in toward Willow Grove from the main road they broke into a run and raced into the woods, shouting and yelling like wild Indians. Once in the friendly shade of the trees they capered about in the joy of their Saturday freedom. Chet took charge of the lunches and stored them in a convenient clearing, and then began the rush for the river. The day passed in the usual fashion of such days. They swam, they ate, they loafed about under the trees, they played games at imminent risk of life and limb, they explored the woods, and otherwise enjoyed themselves with all the happy energy of healthy lads. Joe Hardy, who was an amateur naturalist in his way, went roaming off by himself during the afternoon while the other boys were enjoying their third swim of the day, and penetrated deeper into the woods. He poked about in the undergrowth, examining various flowers and plants that came to his attention, but discovered no specimens that he had not seen before. He was just on the point of going back to the other lads when he saw before him a small clearing. It was a part of the grove in which he had never been, so he ploughed on through the bushes until he found himself in a clearing that appeared to be part of an abandoned roadway. It was in a low-lying part of the grove and the ground was wet. At one point it was muddy, and in this mud Joe saw something that aroused his curiosity.