This book covers the part of the Revenge of the Fallens movie, from rescuing Megatron to appearance of the Fallen in various battles. No resolution to the battles as that's part of the next book in the series!
This book is a Level 2 book, where kids 4 - 6 can follow. Now why would a young kid be interested in this book? Despite the movie being PG-13, I'll say good 50% of it is fine for kids of these age if the parent can control the scenes. And for kids loving Transformers movie figures including fascination into the Decepticons (but still believe in good beats the Evil of course), this book provides a real training-to-read opportunity as incentive is there for the young ones.