Gehenna is the time when the Antediluvians (the grandchildren of Caine, the first vampire) will rise to consume the blood of all the younger vampires and construct a city in which they will rule for one thousand years. The prophecy of Gehenna is most thoroughly detailed in the Book of Nod, the story of Caine's banishment and cursing by God. There are also portents found in the Book of Nod, claiming the coming of the "Dark Father" and the "Dark Mother". Who these are is uncertain, but it is believed these two figures could be the mythical Caine and Lilith, respectively. Gehenna is said to be preceded by the Time of Thin Blood, in which successive generations of vampires past the thirteenth lose the potency of their blood, become incapable of siring childer or exercising their vampiric powers, and even develop a tolerance to sunlight.
Four possible Gehenna scenarios were depicted in the final Vampire: The Masquerade sourcebook, which was titled Gehenna, as part of the Time of Judgment that ended the original World of Darkness. The four scenarios are:
"Wormwood" (God destroys all vampires save for a few, who are given a chance at redemption)
"Fair is Foul" (Lilith takes her vengeance on Caine and his descendants)
A Gehenna cult is a group of individuals (almost always vampires) that is devoted to influencing events leading up to or during Gehenna, often with the objective of stopping or aiding the Antediluvians. While these cults vary widely and are often in opposition of one another, in general each focuses on one or more similar activities including:
The term is used somewhat derisively, as most Kindred do not believe in the Antediluvians and many Gehenna cults are pseudo-religious, fanatical, and lacking any trusthworthy information. Many assume that they are created by elders to dupe younger vampires into unknowingly taking part of their personal schemes. The entire Sabbat could be called a Gehenna cult (and often is by members of the Camarilla), but the term is normally reserved for much smaller groups including:
The Royal Order of Edenic Groundskeepers. Founded in AD 1645, the Groundskeepers seek first and foremost, the resting-places of the Antediluvians. They are scholars who now possess the most extensive library of Kindred archeology in existence.
The Imperial Order of the Master Edenic Groundskeepers. Founded in AD 1898, this offshoot of the Royal Order of Edenic Groundskeepers gathers the recruits and weapons needed for a full-scale assault on the purported 62 tombs of Antediluvians and Methuselahs.
The Way of the Ancient Lawgivers. Founded in AD 1312, the Lawgivers (also known as "Enochians") argue that if the Kindred return to the ways of Enoch the First City - by which they mean that vampires should overtly enslave humanity and institute a strict hierarchy of age - the Ancients will have mercy and bring an era of unparalleled peace when they rise.
The Servitors of Irad. Founded in AD 1456, the goal of Servitors is to aid the Antediluvians' return to power by leading Kindred society ever deeper in obscurantism so that it will be less able to defend itself.
The Twilight Cult. Founded in AD 1550, the Twilight Cultists seek a woman referred to in The Book of Nod as "the last daughter of Eve."
The Cult of Enlightenment. Founded in AD 510, the Enlightened pursue the near-futile task of bringing spiritual enlightement of the Kindred race by encouraging them to transcend the Beast.
The Arimatheans. Founded in AD 30, the Arimatheans seek the Holy Grail as the ultimate vessel for not only their own redemption and transfiguration but that of Father Caine and, by extension, the whole race of vampires as well.
The Lilith Cults. The Lilins (or "Bahari" as they call themselves) are dozens of small, disparate cults that worship their Dark Mother, Lilith.
Seer Cults. Founded in recent nights, many cults are forming around thin-blooded vampires, with mystical insights about the Jyhad, hailed as messianic figures who could guide the Kindred into a new age of peace and wisdom.
The Heralds of the Red Star. The most famous seer cult (named for the star that appeared prior to the "week of nightmares" and led by half-human/half-vampire prophet V. Harriet Bakos) whose self-appointed mission is to convince the rest of the Kindred race that the end is much closer than is widely believed, and that differences must be put aside now if vampires hope to endure.