The Sea of Monsters by Rick Riordan

This is a wonderful sequel to The Lightning Thief. It shows you impossible situations that the main characters somehow solve. When they figure out things in this book you immediately think,"Wow, that's true, I never thought of that!". In this book they have to find the golden fleece. This fleece is magical and can heal anything, including a magical tree which they need to heal to save all the half bloods. If you don't understand what I just said you can read both books because this one is ages 10 and up! This book does require that you read the first book first.