This is the third book in this series that i have recently read. I like these books as a whole, but am not thrilled with the ebook formatting. This particular book deals with energy, creating, storing, using, etc. I like that they have added the pink and yellow lightning bolt that tells how long, how easy, how messy, and how to be safe. Not my favorite book, but full of fun ideas for kids to try on their own, or with others.