Good continuation but disappointing
If your kids read the first book in this series, you have a good grasp on what to expect. I think this book is good for kids who have been exposed to a lot of stuff already but not good for kids who are more sensitive or very conservative families of a 10 year old (I would recommend a little older). One thing not included in the site review is the mention of Nirvana music and lyrics. I found their inclusion to be completely inappropriate and frustrating. There is also some boy-girl flirting and teasing, which I think is completely unnecessary for a target audience of under 12.
The best part about this book is that it will make kids curious and excited about history and historical figures and places, which should spur some fun investigations.