I read this book because the mention of time travel in the description intrigued me. Unfortunately, this element doesn't show up until 2/3 through the book, and even then, it's not very extensive.
I also really didn't like the portrayal of gender in this book. The male characters get to go on adventures and try to save the day, but the female characters are always damsels in distress who are purposefully kept out of the loop.
Yet, it's great in the chiller-thriller department. Most tween and teen boys would probably enjoy this book a lot more than I did.