In the book "The Seven Wonders: The Tomb of Shadows" by Peter Lerangis (Harper), Jack and his friends go on a hunt for the Loculus and his mom. There are some hurdles to jump before they get there, including a secret portal.
The book is mostly about Jack and his friends Cass, Aly, Marco and Torquin going to different places to get hints to find the three Loculi. When they are so close to getting the three Loculi, they find out they have been betrayed.
What I liked about the book is there is a lot of action and they're always on the move. My favorite character is Torquin. I like Torquin because he's 7 feet tall and I love basketball and he plays a good role.
I like how the story is written -- you can't get bored reading this because they're always on the move. I also like this book because I am learning about one of the seven wonders in social studies and some of the events take place around the things we're learning about in class.
Overall, this is a great book. This book is part of a series but it is not necessary to read the first two. I think kids ages 8 to 12 should read this. The author also wrote the "39 Clues" book series in case you're interested in that.