Zip followed the boys about the barn as they poked into all the nooks and corners. Tom, as every one called the hired man, was busy about his work and paid little attention to Laddie and Russ. It was about half an hour after the boys had gone out to the barn, and Mrs. Bunker was wondering if they were all right, when Laddie came running to Grandma Bell's house, very much excited and out of breath, crying: "Oh, come quick! Come quick!" "Mercy me! what's the matter now?" asked Mrs. Bunker. "Russ can't stop! Russ is going and he can't stop!" panted Laddie. CHAPTER XIII THE RED-HAIRED MAN For a moment or so no one seemed to know what answer to make to Laddie. He stood there, all out of breath, looking at his father and mother and Grandma Bell, who were sitting on the side porch. "What--what did you say?" asked Mr. Bunker. "It's Russ," Laddie answered. "He's going and he can't stop! I tried to make him, and he tried himself, but he can't stop, and he's running like anything!" "What in the world does he mean?" asked Mother Bunker. "Tell me about it!" said Grandma Bell. "It's out in the barn," explained Laddie. "Russ got on something, and he can't stop running!" "Maybe he's in a trap!" exclaimed Laddie's mother. "If he was in a trap he couldn't run," said her husband. "I'll go out and see what it is." The other little Bunkers were still playing with Muffin, the big gray cat, as Mr. and Mrs. Bunker and Grandma Bell hurried out to the barn. As they drew near it they heard a voice shouting: "Oh, make it stop! Make it stop going! I'm so tired! My legs are so tired!" At the same time a low rumbling could be heard, like that of very distant thunder. "Oh, what is it?" gasped Mother Bunker. "Oh, Russ, what have you done now?" But a moment later they were all relieved to see Tom, the hired man, come to the door of the barn, leading Russ by the hand. The boy looked frightened, but not hurt. "What was it?" asked his father. "I got to going and I couldn't stop," explained Russ, who was breathing almost as hard as Laddie had done after his run. "What did you get to going on, and why couldn't you stop?" his mother wanted to know. "Oh, it was a--a sort of wooden hill," explained Russ. "I was running on it and----" "What does he mean--a _wooden hill_ in the barn?" asked Mrs. Bunker. "It was the treadmill," explained Thomas Hardy. "I was in another part of the barn, and I guess Russ must have wandered upstairs, where we keep the old treadmill they used for the threshing machine and churn. He started to walk on the wooden roller platform, and it moved from under him. He had to keep running so he wouldn't slip down. That's what he meant when he said he couldn't stop." "That was it," explained Russ. "I saw a funny machine upstairs in the barn, and I got on it. I didn't know it would move."