The Nancy Drew Notebooks are a series of books featuring the amateur sleuth Nancy Drew. The stories are aimed at younger readers and portray an 8-year-old Nancy and her friends in the third grade. Brenda Carlton, who appears in the Nancy Drew Files and the SuperMysteries, also appears in this series. The books are illustrated by occasional black and white drawings. The "notebook" in the series title refers to the "blue notebook in which [Nancy] keeps track of her mysteries and writes down what she learns". The stories end with a moral message telling the reader what Nancy has learned. The cover layout has changed and evolved throughout the series. It was initially published by the Minstrel imprint and later switched to the Aladdin imprint. The series ended with volume #69 in December 2005,