The Apocalypse (Apocalypse World)

The Apocalypse in the Apocalypse World is both a war between the forces of Heaven and Hell and a war of genocide on the remaining human population of Earth by the angels led by Michael.

Prelude
In 1973, after contacting Lucifer at St. Mary's Convent, the Prince of Hell Azazel begins making a series of deals in order to create his Special Children. After killing John Winchester, Azazel offers a deal to Mary Campbell resurrect John if she gives him permission to enter her house in ten years. However, unlike her Main Universe counterpart, Mary refuses the deal and John remains dead.

As a result of Mary refusing the deal, she remains alone for the rest of her life and never moves on from John. With their father dead, Sam and Dean Winchester never come into being. Mary became good friends with fellow hunter Bobby Singer, saving his life several times. In about 2007, Mary is killed by Azazel.

Rise and Fall of Lucifer
At an unknown point in time after 1973, Azazel's plan came to fruition and Lucifer was released from his Cage in Hell. When Lucifer and his demons rose from Hell, the human race believed the angels to be their saviors, but the angels turned on the humans one by one. With Sam and Dean Winchester not existing in this world, the war was not stopped and consumed the planet, leaving much of the Earth in ruins. Finally, Michael was able to tear Lucifer apart in the skies over Abilene. Despite this, the angels and demons remained locked in combat with what was left of humanity caught in the middle. Demons such as Tempter Demons continued to roam the surface of the Earth by May, 2017.

Genocide of the Human Race
At some point before or after the defeat of Lucifer, the angels, commanded by Michael turned their attention towards exterminating the human race. The remainder of humanity is relegated to small colonies that are targets for any angels that locate them. Angels are known to "dive-bomb" human colonies and wipe out every single person they can find. Human survivors are often left sporting various injuries and are protected by the remaining hunters in the world. At least some hunters take pleasure in hunting down any angels they can find as a result.

Intervention from a different reality
In May, 2017, the birth of the Nephilim Jack opens a rift between the Main Universe and Apocalypse World. After seeing the rift, a curious Castiel enters and is saved from a Tempter Demon by Bobby Singer who is investigating the rift which set off "all sorts of alarms" with the added intention to kill any angels that come to investigate.

Recognizing that Castiel is different to the angels in his world, Bobby spares Castiel's life and explains the history of Apocalypse World. Sam and Dean Winchester soon come through the rift as well and meet Bobby who lends Dean his gun loaded with angel-killing bullets to use against the Lucifer of the Main Universe. Together, the Winchesters, Castiel and Crowley embark upon a plan to trap Lucifer in Apocalypse World, a plan that leaves Castiel and Crowley dead and Lucifer and Mary Winchester trapped with no way back as the rift is sealed.

After an encounter with several angels, Lucifer and Mary are discovered by Michael who is confused as the Lucifer he knows is dead. Being stronger than the Michael Lucifer is used to, Michael overpowers Lucifer and takes him and Mary captive. After torturing Lucifer, Michael learns of the history of the Main Universe and decides to launch an invasion of the Main Universe. An attempt by the Prophet Kevin Tran to open a rift for Michael enables Lucifer to escape, albeit with depleted grace, to warn of the impending invasion.

Months after the opening of the rift between the worlds, Jack attempts to find a way back to rescue Mary. To this end, Jack and the Winchesters enlist the aid of dreamwalkers Derek Swan and Kaia Nieves to open a new door between the worlds. Due to Kaia flashing between Apocalypse World and the Bad Place, Jack is transported to Apocalypse World while the Winchesters end up in the Bad Place.

Following their rescue from the Bad Place, the Winchesters eventually learn of the threat of Michael's invasion from Castiel and set out to find a way back to Apocalypse World to rescue Mary and Jack. With the help of Donatello Redfield and the Demon Tablet, the Winchesters attempt to recreate the spell the alternate Kevin used to open the rift Lucifer came back through while Asmodeus obtains an Archangel Blade, the only weapon capable of killing an archangel such as Lucifer or Michael. Though Donatello is able to translate the spell, he is corrupted by the power of the demon tablet in his soulless state and the spell has to be stripped from his mind by Castiel.

After his arrival, Jack is captured by Michael who attempts to use Jack to open a rift between the worlds for Michael to lead an invasion force through. Following a failed attempt by Zachariah to trick Jack into helping the angels, Jack and Mary team up together to escape from Michael's fortress. Shortly after their escape, the two are found by Bobby Singer and taken to his colony, one of the few remaining human colonies left.

In the colony, Jack and Mary bear witness to the full effects of the Apocalypse on Apocalypse World and learn of the extermination of the San Antonio colony and four hundred people just two days before. While in the colony, Mary and Bobby discuss Mary's counterpart and Mary learns of her counterpart's refusal to make a deal with Azazel to bring John Winchester back. Mary realizes and reveals to Bobby that the Apocalypse in Apocalypse World happened because Sam and Dean didn't exist to stop it due to her alternate self's choice.

After learning that Jack is a Nephilim, Bobby exiles him from the colony due to a belief that its only a matter of time before Jack turns on them as a half-angel. During his time in the colony, Jack grows attached to the people who he feels are brave for surviving all that they have endured. Before Jack and Mary can leave in the morning, the colony comes under attack by Zachariah and several angels. Despite orders to run and hide, Jack intervenes to kill Zachariah and three other angels, saving the colony from destruction.

Following the defeat of the angel attack, Jack gains acceptance by Bobby and the humans. Jack realizes that the angels are indeed waging a war of genocide and will not stop until the human race is extinct. As a result, Jack decides that he must kill Michael to end the Apocalypse and save what is left of the human race.

Resistance
Following the Attack on the Human Colony, Jack and Mary Winchester began helping the people of Apocalypse World form a resistance against the angels. Charlie Bradbury becomes a high-ranking member of this resistance.

Months after the formation of the resistance, Dean returns to Apocalypse World with Arthur Ketch in an attempt to rescue Mary and Jack. The two witness the execution of a few resistance members and Charlie being taken for interrogation on the resistance. Still feeling guilt over the murder of his Charlie Bradbury, Dean convinces Arthur to help him launch a rescue mission for Charlie. Dean and Arthur liberate a POW camp, killing several angels and setting the prisoners free.

Out of time before the rift between the worlds closes, Dean returns to the Main Universe while Arthur remains in Apocalypse World to locate Mary and Jack and to help the resistance coordinate for Dean's inevitable return with reinforcements.