It requires at least 6 months of preparation, celibacy and abstinence from alcohol. However, it also includes the summoning of the 12 Kings and Dukes of Hell, to bind them and remove their negative influences from the magician's life. Whilst Crowley was in the process of performing the lengthy ritual, he was called to Paris by the leader of the Golden Dawn. According to legend, he never banished the demons he had summoned, leading to strange happenings occurring in and around Boleskine House.