This book hasn't been checked out since 2005 in my library and it's not hard to see why.
Zachary is jealous of Andrea, the daughter of his father's girlfriend. His father is obviously trying to spend more time with Andrea to get to know her and that makes Zachary very jealous. For example, Andrea asks nicely to borrow a colored pencil and Zachary screams "No" at her. Zachary even accuses Andrea of cheating several times when playing a game. Even though the feelings of this child are very realistic and happen in real life, I actually think this book is better for the parent to help them understand the child's feelings than it is for the child to understand the situation.
What was disappointing the most is that I was thinking that maybe Zachary would learn to like Andrea and accept her more and that there would be some great moral to the story, but instead at the end of the story, the very last line, Zach says "I hate it when my father likes Andrea Abbott more than me." Showing that he learned absolutely nothing.
I'm going to be honest. I weeded this book out of the collection because I thought it was so bad. I'm afraid it would give children the wrong message that it's OK to act this way when it's not.