For a series I started after finding the first book at the dollar store, I have to say I really enjoyed these books. This is partly because it's a fantasy series where the different races aren't your typical: elf, orc, giant, dwarf, etc. The author created his own races and his own fantasy world, which makes it new and exciting.
The only reason why this isn't 5 stars is because there is a TON of unnecessary detail in the book. It's very dense; this book is tailored towards 8 year old kids, and no 8 year old is going to be able to get through that. It's by no means difficult to read but I feel like it should really be geared more towards teens. The other problem I had (in all 3 books) was that Jason and Rachel are just too young to be doing what they're doing and comprehending all the crazy things going on. I believe instead of 13 they should have been closer to 15 or 16.It was devastating to see character after character die, and again I think this makes the book a little difficult for an 8 year old to comprehend.
Despite those few problems, I really enjoyed the series and honestly wish there were more books so I could see what happens next.