Supernatural Season 8 Complete

One year after the defeat of the Leviathans, Dean escapes Purgatory, with a vampire-comrade-in-arms named Benny, and reunites with Sam ...

One year after the defeat of the Leviathans, Dean escapes Purgatory, with a vampire-comrade-in-arms named Benny, and reunites with Sam who has retired from hunting much to Dean's anger. Not long after Dean discovers that Kevin had escaped Crowley's abduction months ago which Sam was unaware of. Kevin reveals that he stole another Word of God from Crowley about Demons and discovered the means of closing Hell forever with all demons inside. Now reunited Sam and Dean embark on their monster hunts while Kevin continues to translate the tablet to stop Crowley and his plotting.

Sam and Dean's relationship is challenged as Sam stopped hunting for a year which he claims is because he had no one to force him anymore with Dean and Castiel gone, Bobby dead and Kevin and Meg missing. Dean, however, remains in contact with Benny, who is trying to live without killing but is missing Purgatory but Sam becomes angry that Dean would let a vampire live.

The season also features flashbacks in both Sam and Dean's past year on Earth and Purgatory. For Dean he constantly fought monsters everyday for a year in Purgatory until Benny saved him and told him of a portal which could transport humans out. Dean and Benny find Castiel and the three fight past Leviathans to make it to the portal but Castiel refuses to leave. As for Sam, he retired from hunting and met a woman named Amelia and lived a normal life with her. However, once she discovers that her husband, a soldier presumed KIA, was still alive, Sam left to allow her to reunite with him. Eventually Castiel returns, freed from Purgatory by the mysterious but powerful angel Naomi, who has apparently taken control of Heaven and puts Castiel under her control to spy on the Winchesters for her own motives. Meanwhile, Amelia returns to Sam to re-connect but Sam pushes her away for good while Benny helps Dean by dying and returning to Purgatory to help Sam and Bobby pass through Purgatory to Earth and subsequently chooses to stay there.

Kevin eventually learns the three trials for sealing Hell from the Demon Tablet: kill a Hellhound and bathe in its blood, free a soul from Hell (who turns out to be Bobby) wrongfully imprisoned, and finally cure a demon who they choose to use on Crowley. However, the Winchesters and Castiel learn from Meg, before she is killed by Crowley, of the Angel Tablet which Naomi tries to have Castiel steal for her own uses but he resists and flees from everyone. Additionally, Sam and Dean encounter their grandfather Henry and a powerful demon named Abaddon who is a Knight of Hell, among the oldest and most powerful demons. While Henry is killed and Abaddon is decommissioned, the brothers lean of a bunker belonging to the Men of Letters, the collectors of information on the supernatural who entrust a few hunters to handle the most powerful monsters. In the midst of the trials, Sam and Dean encounter an angel named Metatron, the Scribe of God and the creator of the tablets who then reveals the nature of the angel tablet to Castiel: to seal Heaven and its angels and works with Castiel to fulfill this mission. Meanwhile, after Crowley begins killing Sam and Dean's old friends, they decide to give in.

In the season finale, Sam and Dean manage to capture Crowley to use him as the last trial and cure him while Naomi continues looking for Castiel and captures Metatron, forcing Castiel to work with Dean to finish the angel trials. Meanwhile, Sam is interrupted by Abaddon but fends her off as Crowley begins to show signs of humanity. Naomi realizes that Metatron is not planning to seal Heaven but is planning to break Heaven and cause the angels to fall and that if Sam completes the final trial, he will die as God wanted. Dean returns to Sam and in an emotional breakdown they make up for their years of mistakes but Sam passes out while Metatron betrays Castiel and takes his grace, turning him human. Moments later the angels of Heaven fall all across the Earth as Sam, Dean, Kevin, Castiel, and Crowley are forced to watch helplessly.