This book was amazing!! It's a companion to Wonder, so if you have not read it some parts won't make sense, and there would be some spoiling. Anyways, Pluto is about the day of one of August Pullman's best friend Christopher. There are some flashback scene chapters, and the other chapters are times of day (example: Chapter one is called "7:08 am".). There are a couple parts that are slow, but it is completely worth it if you liked Wonder!
-Madeleine