“I don’t know,” answered Fatty. “Never knew him to get excited about cows before. Here, Hopper, where are you going?” he yelled as the dog, with loud barks, rushed for the herd of cows. “Come back!” But the hound did not obey. And then Teddy and his chums saw the reason. In with the herd of cows, cropping grass as they were, stood an animal with branching horns. “Look!” yelled Teddy. “The mystery deer! There he is!” “Golly! Sure enough, it is the deer,” echoed Joe. “But the dog! The dog!” cried Dick. “He’ll kill the deer! Call him back, Fatty!” “Here, Hopper! Hopper! Come back!” ordered the fat boy. But the hound, with loud barks, was leaping toward the herd of cows in the midst of which was the strange deer. The cows separated as the dog rushed toward them, leaving a cleared space in the middle of which stood the deer who threw up his head and looked at the oncoming dog. “Your dog will pull the deer down and kill him, Fatty!” cried Teddy. “Can’t you bring him back?” “I’ll try,” said the fat boy, running after his dog. “Back, Hopper!” Just when it seemed that the dog was about to jump on the deer, which seemed too frightened to run, a man suddenly leaped over the fence and took his place in front of the deer. There was something familiar about the man. And when he began swinging a rope in circles around his head Teddy cried: “It’s the lasso cowboy!” It was, and in another instant the loop of the lasso had settled over the head of the big hound. With a quick jerk on the rope the cowboy pulled the dog off its feet. “Good work!” yelled Teddy. “Now the deer is safe,” said Dick. “He lassoed your dog just in time, Fatty,” said Joe. “Yes, but I hope he doesn’t hurt him,” spoke the stout lad. “Hopper is a good dog but he gets excited when he sees a deer.” The lassoing of Hopper seemed to have taken all the fight out of the dog. Perhaps he would not, after all, have attacked the deer. But the cowboy was taking no chances. As if sure the dog was no longer a danger, the cowboy took the lasso from the neck of the dog, who had been choked a little. And a moment later the cowboy had secured the deer with the same rope. He did it gently, however. Then, having made the end of his deer lasso fast to the fence, the cowboy walked toward the boys and smiled. “Well,” he said, “I guess the chase is over.” “Is that your deer?” asked Teddy. “No, but I’m responsible for it and I’m glad I have it back. I want to thank you boys for what you did, trying to help capture this deer and I want to tell you I’m sorry I lassoed one of you. Which one was it?” “You lassoed me,” Teddy said with a laugh. “But it’s all right. You didn’t hurt me any.” “But why did you do it?” asked Joe.