Degrees of Horror
Mundo De Los Muertos
The ritual transcribed in Mundo De Los Muertos allows you to call forth a ghost from the spirit world and manifest it as a flesh-and-blood person — more or less. The ghost will only be manifest for a few minutes, and then is returned to whence it came. (Depending on the situation, that could be the after-life, a place being haunted, a body being possessed, etc.)
While manifested, the ghost is bound to the leader of the ritual — the farther apart they are, the weaker it gets. If it gets more than 20 feet or so away, it’s manifestation will end completely. The ghost can be compelled by the lead ritualist to remain silent or to answer specific questions, though it may not necessarily answer truthfully or completely.
This ritual requires some common items such as candles, string, and wood chips. In addition, it requires some exotic items such as a human tooth, a child’s tears, and the dirt of a freshly dug grave. Most of these materials are consumed when the ritual is completed. The ritual works even better when cast on the anniversary of the deceased’s death, on a sacred day honoring the dead, at incredibly high elevations, during a thunder storm, or using the grave dirt from the spirit’s own grave. (The human tooth or child’s tears consumed in the ritual, however, can not be from the spirit’s own corpse or that of a close family member.)
In addition, you need some kind of physical object to act as a bridge to the deceased’s soul. This can be part of their corpse, or an object closely associated with the person, or the location where they died. Sometimes the blood of a close family member can be used. If the bridge isn’t specific enough, you may accidentally summon the wrong spirit.
This ritual is somewhat crude and amateurish by the standards of occult professionalism. If the ritual is miscast or improper ingredients are used, the results could be… bad. The book does not go into details.