Very intriguing start to cool series. It is not the best in the series, and certainly not the worst. The last couple of books were the worst (Amy fell in love with the wrong person and ended up having her ex-boyfriend die for her even though she really didn't love him anymore and he thought she did). Also, one of the middling books was pretty bad (Amy was falling in love with her COUSIN; like, what the heck?!). Altogether, 'The 39 Clues' is not something I would read again, but it *was* entertaining and overall pretty good throughout. There was a lot of unevenness and ups and downs (probably due to the fact that each book was written by a different author).