Let me make one thing perfectly clear: This book is a companion volume to GURPS Magic. In order to fully appreciate (and make the best use of) this book, you need GURPS Magic as well. Now that that is out of the way, on to the praises. This is where you will find the odder and more esoteric spells (as well as some of the more powerful ones) that Magic just didn't have room for, or that handn't been thought of yet. Some of these spells are exceptionally powerful, others are just plain sneaky, but all are useful. As I said before, the odder corners and more advanced levels of magic are more fully represented in this book, along with optional rules. Here you will find things like techno-magic, radiation spells, acid spells, spells to literally rain fire down upon your foes, a spells to create an imprisoning circle around your foes, spells to fascinate and control your enemy, shapeshifting spells, elaborate illusions, divination spells, and even a spell to plunge a target into a morass of incapacitating pleasure. That little list only scratches the surface, my friends. A few new schools of magic are added, and almost every one of the schools of magic presented in GURPS Magic has additions in this book, and all of them are worth looking at. If you want to be the best magic-user that you can be, this book will help you on your way.
This is basically GURPS Magic, book 2. It provides great additional material in the way of new spells for the current colleges of magic such as the Elementals or Necromancy. In addition, the new schools of magic (Gate and Tech magic) are interesting new additions. This gives your characters the advantage of not only having the right spell for the right occasion, but also having a selection of tricks up their sleeves.
Used with GURPS Magic and the GURPS Basic Set it provides a complete, varied and well integrated set of spells for roleplaying. Without being tied to specific genres it still manages to offer a wide range of dramatic possibilies from which many a plot could be spawned.