Defeating Evil at High School

Arrived late in the night at my old high school with others. The dream had a movie arch or feel to it as though everyone were just playing their characters. I walk up to the upper floors and the library to find that there is some kind of evil being practiced--something involving communication with the devil or some such thing. Some woman had gone to great time and effort to create this device out of crystals and (especially now the dream feels like a movie) I destroy it in front of her, impervious or uncaring to any retaliation. This kind of sequence of me destroying something or causing chaos in the mansion happens a few more times. Later on I realize that they are keeping a slave girl there whom I promised to free. Later still I discover that they're doing time travel on the side and wind up hopping on their backs to travel with them. Now the dream shifts to a third person role and I am more of a spectator, unable to tell the person doing the time travel to save the girl.