He did did something had and lied. He thought no one would find it out, but Tommy happened to see him, and when Emil spoke of it a day or two later, Tommy gave his evidence, and Mr. Bhaer heard it. School was over, and they were all standing about in the hall, and Mr. Bhaer had just sat down on the straw settee, to enjoy his frolic with Teddy; but when he heard Tommy, and saw Nat turn scarlet, and look at him with a frightened face, he put the little boy down, saying, “Go to thy mother, biibchen, I will come soon,” and taking Nat by the hand led him into the school, and shut the door.

Mr. Bhaer had just taken down the long rule that hung over his desk, so seldom used that it was covered with dust.

“My eye! he’s going to come down heavy on Nat this time. Wish I had n’t told,” thought good natured Tommy, for to be feruled was the deepest disgrace at this school.

Tommy regretted telling Mr. Bhaer about Nat's wrongdoing because he knew that Mr. Bhaer would punish Nat severely. The punishment would likely involve using the dusty long rule, a sign that it was a serious offense. Tommy felt guilty for possibly causing Nat such embarrassment and shame.