Something had to be done. Jerry Muskrat said so. Grandfather Frog said so. Billy Mink said so. Little Joe Otter said so. Even Spotty the Turtle said so. The Laughing Brook couldn't laugh, and the Smiling Pool couldn't smile. You see, there wasn't water enough in either of them to laugh or smile, and nobody knew if there ever would be again. Nobody had ever known anything like it before, and so nobody knew what to think or do. And yet they all felt that something must be done.

"What do you think, Billy Mink?" asked Grandfather Frog.

Billy Mink looked down from the top of the Big Rock into the little pool of water that was all there was left of the Smiling Pool. He could see a dozen fat trout in it, and he knew that he could catch them just as easily as not, because there was no place for them to swim away from him. But somehow he didn't want to catch them. He knew that they were frightened almost to death already by the running away of nearly all the water from the Laughing Brook and the Smiling Pool, and somehow he felt sorry for them.

"I think that the best thing we can do is to move down to the Big River. I've been down there, and that's all right," said Billy Mink.

"That's what I think, " said Little Joe Otter. "There's no danger that the Big River will go dry."

"How do you know?" asked Jerry Muskrat. "The Laughing Brook and the Smiling Pool never went dry before."

"It's a long, long way down to the Big River," broke in Spotty the Turtle, who travels very, very slowly and carries his house with him.

"Chugarum! I, for one, don't want to leave the Smiling Pool without finding out what the trouble is.

 "There's nothing happens, as you know,
  But has a cause to make it so.

"Now there must be some cause, some reason, for this terrible trouble with the Smiling Pool, and if we can find that out, perhaps we shall know better what to do," said Grandfather Frog.

Jerry Muskrat nodded his head. "Grandfather Frog is right," said he. "Of course there must be a cause, but where are we to look for it? I've been all over the Smiling Pool, and I'm sure it isn't there."

Grandfather Frog actually smiled. "Chugarum!" said he. "Of course the cause of all the trouble isn't in the Smiling Pool. Any one would know that!"

"Well, if you know so much, tell us where it is then!" snapped Jerry Muskrat.

"In the Laughing Brook, of course," replied Grandfather Frog.

"No such thing!" said Billy Mink. "I've been all the way down the Laughing Brook to the Big River, and I didn't find a thing."

"Have you been all the way up the Laughing Brook to the place it starts from?" asked Grandfather Frog.

"No-o," replied Billy Mink.

"Well, that's where the cause of all the trouble is," said Grandfather Frog, just as if he knew all about it. "It's the water that comes down the Laughing Brook that makes the Smiling Pool, and the Smiling Pool never could dry up if the Laughing Brook didn't first stop running."

"That's so! I never had thought of that," cried Little Joe Otter. "I tell you what, Billy Mink and I will go way up the Laughing Brook and see what we can find."

"Chugarum! Let us all go," said Grandfather Frog.

Then the five put their heads together and decided that they would go up the Laughing Brook to hunt for the trouble.