This Thursday marks an important episode in the Supernatural lore.

Titled "The End," the installment finds Dean waking up five years in the future. He's in an abandoned city and is attacked by humans-turned-zombies that have been infected with a demonic virus.

Dean soon learns that this world exists because, in the present day, he turned down the chance to help the angels fight Lucifer. Oops! Watch a clip from "The End" below:

[video url="http://www.tvfanatic.com/videos/clip-from-the-end/" title="Clip from The End"] [/video]

Relive a few Supernatural quotes from the season to get ready for this week's episode; and click on the pics below for an early look at scenes from it:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.