The Blue Notebook is the eighteenth chapter of Wayside School Gets a Little Stranger.
The students abscond with Mrs. Drazil's blue notebook, intent on reading it. In so doing, they realize that in order to get rid of Mrs. Drazil, they must find Jane Smith, a former student whom Mrs. Drazil dislikes more than Louis. Jane Smith left Mrs. Drazil a nasty note stating that she didn't do her homework (as found in the notebook, it was the 12th time in a row); also, she (at the time the note was written) was moving, and wasn't going to tell Mrs. Drazil where. She closes her note by telling Mrs. Drazil to "rub a monkey's tummy with [her] head."