Necromancy

Necromancy is the practice of magic involving communication with the dead–either by summoning their spirits as apparitions, visions or raising them bodily–for the purpose of divination, imparting the means to foretell future events, discover hidden knowledge, to bring someone back from the dead, or to use the dead as a weapon. Sometimes referred to as “Death Magic”, the term may also sometimes be used in a more general sense to refer to black magic or witchcraft. (Wikipedia)