Sam decides to give up hunting, but a face from his past comes to convince him otherwise.

FREE TO BE ME AND YOU
Season 5, Episode 3

Not sure he trusts himself anymore, Sam decides to give up hunting, but a late-night visit from Jessica Sam's doomed girlfriend who was killed by the demon in the pilot - won't let him off the hook that easily.

Meanwhile, Dean, intent on stopping the Apocalypse, continues hunting on his own and teams up with Castiel to find the Archangel Raphael – as Castiel believes Raphael knows God's location.

THE END
Season 5, Episode 4

Sam tells Dean he wants to rejoin with him in the battle of the Apocalypse, but Dean tells Sam that they are better off apart.

Later, Dean awakens five years in the future in an abandoned city and is attacked by humans who have been infected with a demonic virus that turns humans into zombies. Zachariah appears to Dean and explains that this is the world that exists as a result of Dean saying no to helping the angels fight Lucifer. Dean meets up with the "Future Dean," who tells him that the virus is the Devil's endgame for destroying mankind.