The story revolves around an eleven years old girl Harriet M. Welsch. She happens to be a highly precocious girl who keeps observing her friends and then writes down her observations in her notebook.
She is very sincere in her observations, as several of her observations are not kind. When the notebook is discovered by her friends and they read what Harriet has written about them, they are obviously hurt and angry. To express their resentment, they ostracize Harriet. They begin to make plans to avenge themselves and get back at Harriet.