5 out of 5 stars.
I absolutely adore this trilogy. In a world where the undead can be bound and manipulated, Necromancers can control the dead with musical pitches (pan pipe for learners, handbells for experts). Good necromancers help to calm the dead while evil seek to raise an army of zombies. (Just as a side note, I have often noted that the more ridiculous a premise or explanation sounds when describing a book, the more fantastic it turns out to be. I know controlling zombies with music is a strange one, but it is just done so damn well that you are willing to grant Garth Nix anything later on.) Lirael is a daughter of a tribe of future-seers whose gift has not quite blossomed. Her two friends are a magical creature in the shape of a dog, and a future necromancer who is afraid of the dead. One of the things I adore about these books is you have two protagonists of opposite genders who DO NOT FALL IN LOVE. They are friends. They can rely on each other. They have a relationship. But they do not necessarily have to fall in love.
The afterworld in this series is one of its best features. Souls are sucked through levels of a watery world, and the deeper you go, the more desperate the dead are to escape. Necromancers can venture in to rescue souls or others of their kind, but the further in you go, the more death calls to you and the greater the chance of being killed or overtaken by the vengeful dead.
This series, like all Garth Nix, contains a completely formed world, with surprises everywhere. It was just scary enough to be suspenseful and exciting, without keeping me up at night. The system of magic, like the system of death, is unique and detailed. Garth Nix is able to do what many authors cannot and manages to build worlds robust enough to seem to be able to stand on their own. I have read this series 4 or 5 times and intend to keep on rereading it until I have it memorized or all copies have been erased from this world. Well done Garth Nix! I consider this a must-read for everyone, but if you are especially looking for great high fantasy, or a zombie thriller that involves magic, this is the book for you.