Until the beginning of the 20th century, farmers in Gascogne (France) believed that villains avenged themselves on their enemies by having a priest perform the Mass of Saint-Sécaire.
It is not commonly known amongst priests, and of those who do, only a handful dare performing it. Only the most corrupted and depraved priests are willing read this mass, and they can be sure that they will pay heavily for this on Judgement Day. No other priest or bishop, not even an archbishop, can absolve this crime; only the Pope of Rome has this right.
As is often with such rituals, there are certain obscure and sinister conditions under which it must be performed.The priest must, accompanied by a harlot (who is also his lover), travel to a ruined or deserted church, where bats hang from the ceiling, where gypsies spent the night and where toads live under the desecrated altar.
The evil priest will then begin to read the Black Mass backwards at exactly eleven o’clock, and he must be finished when the clock strikes midnight. The harlot will act as his precentor during this ritual. The host he blesses is black and triangular; he consecrates no wine, but instead he drinks water from a well in which the lifeless body of an unbaptized child has been thrown. He draws the sign of the cross, but on the ground and with his left foot. Besides these acts, there are many more; some of which the merest glimpse will make a good, faithful Christian go blind, mute and deaf for the rest of his life.
The person for whom this mass was read will gradually start to waste and nobody can tell what is wrong, not even doctors, and there is no cure for it.
by Micha F. Lindemans