The Book of the Law

The Book of Law is a grimoire written by Aleister Crowley, back when he was the most renowned magician on the Magic Side. It's undecipherable, not because of the difficulty to come up with a coherent reading, but because there are hundreds of possible ways to read the grimoire. On its cover apart from the title, are the words 'Liber AL vel Legis', which roughly means 'It will be as you wish it', which emphasises this fact. Index herself cannot unlock its secrets and can only memorise the words without knowing its meanings.

The Book of Law, along with� Ursulas Aquinas, is the� main reason behind the conflict in� Vol.7.�

(Canon) Theories on the Book of Law

 * Anyone that can unlock its secrets will obtain power on par with that of an Angel's.
 * If it's deciphered, it will mean the end of the age of the world� that's controlled by Christianity, and the beginning of a new one.
 * Crowley used the book to predict the future, and as a guide when he's in dire situations. This grimoire is said to be the grimoire that decided the recent history of Western Magic.

Contents of the Book of Law
Apart from the various theories, according to Index what the Book of Law holds is events that happened to Aiwass. Though it's not known who Aiwass is, theories on that range from it being Crowley's guradian angel, to a criminal. As of Vol.19 it's confirmed Aiwass is Crowley's guardian angel of sorts.