“What is the trouble?” cried Spotty the Turtle and Grandfather Frog and Billy Mink and Little Joe Otter together.  “Is the hole filled up with stuff that has drifted in?”

Jerry shook his head, as he slowly climbed out of the water.  “No,” said he.  “No, it isn’t filled with drift stuff brought down by the water.  It is filled with sticks and mud that somebody has put there.  Somebody has filled up the hole that I worked so hard to make yesterday, and it will take me all day to open it up again.”

Then Grandfather Frog and Spotty the Turtle and Billy Mink and Little Joe Otter and Jerry Muskrat stared at one mother, and for a long time no one said a word.

CHAPTER XXI:  Jerry Muskrat Keeps Watch

 “The way in which to find things out,
  And what goes on all round about,
  Is just to keep my two eyes peeled
  And two ears all the time unsealed.”

So said Jerry Muskrat, as he settled himself comfortably on one end of the new dam across the Laughing Brook deep in the Green Forest and watched the dark shadows creep farther and farther out into the strange pond made by the new dam.

“I’m going to find out who it is that built this dam, and who it is that filled the hole I made in it!  I’m going to find out if I have to move up here and live all summer!” The way in which Jerry said this and snapped his teeth together showed that he meant just what he said.

You see Jerry had spent another long, weary day opening the hole in the dam once more, only to have it closed again while he slept.  That had been enough for Jerry.  He hadn’t tried again.  Instead he had made up his mind that he would find out who was playing such a trick on him.  He would just watch until they came, and then if they were not bigger than he, or there were not too many of them, he would —­ well, the way Jerry gritted and clashed those sharp teeth of his sounded as if he meant to do something pretty bad.

Billy Mink and Little Joe Otter had given up in disgust and started for the Big River.  They are great travelers, anyway, and so didn’t mind so much because there was no longer water enough in the Laughing Brook and the Smiling Pool.  Grandfather Frog and Spotty the Turtle, who are such very, very slow travelers, had decided that the Big River was too far away, and so they would stay and live in the strange pond for a while, though it wasn’t nearly so nice as their dear Smiling Pool.  They bad gone to sleep now, each in his own secret place where he would be safe for the night.

So Jerry Muskrat sat alone and watched.  The black shadows crept farther and farther across the pond and grew blacker and blacker.  Jerry didn’t mind this, because, as you know, his eyes are made for seeing in the dark, and he dearly loves the night.  Jerry had sat there a long time without moving.  He was listening and watching.  By and by he saw something that made him draw in his breath and anger leap into his eyes.  It was a little silver line on the water, and it was coming straight towards the dam where he sat.  Jerry knew that it was made by some one swimming.