The next day, when dinner was about to be served, Uncle Fred came in looking rather thoughtful.
"Has anything happened?" asked Mother Bunker.
"Yes," he answered. "Some more of my cattle have been taken. I thought this would happen after the spring started to go dry. I wish I could find out what it all means—why the water runs out of the spring, and who is taking my cattle."
"I wish we could help," said Daddy Bunker. "But we don't seem able to. The engineers you asked about it don't seem to know what makes your spring go dry; the books tell nothing about it, and we can't find any of your lost cattle. I'm afraid we Bunkers aren't helping any."
"Well, I like to have you here!" said Uncle Fred. "Three Star Ranch would be lonesome if the six little Bunkers went away. Just stay on, and maybe we'll solve the riddle yet."
They were just going in to dinner, when a cowboy rode up on a pony that was covered with foam, from having been ridden far and fast.
"What's the matter?" asked Uncle Fred, as he went out to talk to the man—for cowboys are men, though they are called boys. "Are any more of my cattle gone?"
"No, but they're likely to be. There's a big prairie fire started some miles south of here, and the wind is blowing it right this way. We've got to do something if we want to save the ranch houses from burning!"