Across the Old Pasture to the foot of the Mountain back of the Green Forest tramped Farmer Brown's boy. Ahead of him trotted Bowser the Hound, sniffing and snuffing for the tracks of Reddy or Granny Fox. Of course he didn't find them, for Reddy and Granny hadn't been up in the Old Pasture for a long time. But he did find old Jed Thumper, the big gray Rabbit who had made things so uncomfortable for Peter Rabbit once upon a time and gave old Jed such a fright that he didn't look where he was going and almost ran head-first into Farmer Brown's boy.

"Hi, there, you old cottontail!" yelled Farmer Brown's boy, and this frightened off Jed still more, so that he actually ran right past his own castle of bullbriars without seeing it.

Farmer Brown's boy kept on his way, laughing at the fright of old Jed Thumper. Presently he reached the springs from which came the water that made the very beginning of the Laughing Brook. He expected to find them dry, for way down on the Green Meadows the Smiling Pool was nearly dry, and the Laughing Brook was nearly dry, and he had supposed that of course the reason was that the springs where the Laughing Brook started were no longer bubbling.

But they were! The clear cold water came bubbling up out of the ground just as it always had, and ran off down into the Green Forest in a little stream that would grow and grow as it ran and became the Laughing Brook. Farmer Brown's boy took off his ragged old straw hat and scowled down at the bubbling water just as if it had no business to be bubbling there.

Of course, he didn't think just that. The fact is, he didn't know just what he did think. Here were the springs bubbling away just as they always had. There was the little stream starting off down into the Green Forest with a gurgle that by and by would become a laugh, just as it always had. And yet down on the Green Meadows on the other side of the Green Forest there was no longer a Laughing Brook or a Smiling Pool. He felt as if he ought to pinch himself to make sure that he was awake and not dreaming.

"I don't know what it means," said he, talking out loud. "No, Sir, I don't know what it means at all, but I'm going to find out. There's a cause for everything in this world, and when a fellow doesn't know a thing, it is his business to find out all about it. I'm going to find out what has happened to the Laughing Brook, if it takes me a year!"

With that he started to follow the little stream which ran gurgling down into the Green Forest. He had followed that little stream more than once, and now he found it just as he remembered it. The farther it ran, the larger it grew, until at last it became the Laughing Brook, merrily tumbling over rocks and making deep pools in which the trout loved to hide. At last he came to the edge of a little open hollow in the very heart of the Green Forest. He knew what splendid deep holes there were in the Laughing Brook here, and how the big trout loved to lie in them because they were deep and cool. He was thinking of these trout now and wishing that he had brought along his fishing rod. He pushed his way through a thicket of alders and then--Farmer Brown's boy stopped suddenly and fairly gasped! He had to stop because there right in front of him was a pond!

He rubbed his eyes and looked again. Then he stooped down and put his hand in the water to see if it was real. There was no doubt about it. It was real water--a real pond where there never had been a pond before. It was very still there in the heart of the Green Forest. It was always very still there, but it seemed stiller than usual as he tramped around the edge of this strange pond. He felt as if it were all a dream. He wondered if pretty soon he wouldn't wake up and find it all untrue. But he didn't, so he kept on tramping until presently he came to a dam--a splendid dam of logs and sticks and mud. Over the top of it the water was running, and down in the Green Forest below he could hear the Laughing Brook just beginning to laugh once more. Farmer Brown's boy sat down with his elbows on his knees and his chin in his hands. He was almost too much surprised to even think.