I have read and purchased all of Garth Nix's series.
The Old Kingdom
The Keys to the Kingdom
The Seventh Tower
The Seventh tower was one of my first novels that I read, along with
Deltora Quest (do not be fooled by the name and the comments that other people give about it being a "kids" book, great novels such as this have no age limit
) and I must say, I was thrilled by the story as it went, it was full of twists and turns, it was about friendship and bonds that needed to be kept. It was really something to enjoy.
The other books, were even better. The Old Kingdom was the most interesting book of the three triologies. It placed in modern time and was just interesting when it was storyline, and very heart-racing when it was a battle. This series was my favourite of the three.
The Keys to the Kingdom. I borrowed
Mister Monday from my school library, and after I read it, I just kept reading (I never leave a series unfinished). For some people who say that the first book was a little boring, it was indeed.
BUT it gets so much better as it goes.
I am not kidding when I say this, and I know alot of other people will agree with me...The ending was not what I expected at all, I was just shocked to find out that the ending I predicted was completely wrong. Great ending of course, but I was just too shocked. I shut the book and went to sleep xD
His books are very great, they are a POV kind of book, and most of whatever you read you feel like you're right there with the characters. Garth Nix is a very great author and I advise you to check out all his trilogies.
Happy reading.