The usual short "previous" clip ends, and NOW: the story begins in the 100 mile wilderness in Alaska One year after the end of season 7. A couple are camping out in the forest, and a blinding light appears around their tent. The girl notices this and tries to wake her boyfriend. When he wakes he doesn't believe her, till a dark shadow passes their tent. The girl sends the dude out to investigate with a flashlight. Thinking its a deer, he is about to re-enter the tent when BAM! Dean Winchester, all bloody and tired, appears holding a gun. He questions the frightened kids as to where he is, and when they dont reply, he asks where the road is. He then leaves.
Four days later, Dean gets out of a truck he has hitched a ride in to Clayton, Lousiana. Walking to an old windmill, he takes a spade and starts digging. He comes across old bones, then takes out his hidden left arm, which appears to have SOMETHING in it. He cuts his arm open and lets a bright light into the grave. After a few moments, a man appears and thanks Dean. They part ways. Scene Ends.
In Kermit, Texas, Sam Winchester is awake at home. He pats his dog, and leaves the house, dog and a sleeping girl who is actually awake (classic). He then drives away in the old Impala, unaware he is being watched. In Whitefish, Montana, Sam arrives at an old shack that is obviously full of demon traps. As he walks in, he is attacked by Dean, thrown to the floor, and Dean dumps holy water on him, Bleach, and then cuts him to prove he isn't a monster. Dean then forces Sam to do the same to him, but when he doesn't, Dean does it to himself. Dean says Castiel never made it out. They reunite and within seconds are in a brotherly argument (as usual) this time because Sam admits to having quit hunting, and also that he never looked for Dean when he disappeared.
After settling things out, Sam fixes dinner while Dean catches up on life. While Dean takes out their old mobiles and checks messages, Sam has dinner. Soon Dean finds a load of messages from Kevin, the Prophet from season 7. He has apparently escaped from Crowley and needed Sam's help. However since Sam had quit hunting, he never got the messages. As they finish off the last message, Sam tells Dean that something isnt right in the last one, so they check it out and find that in the background, the stewardess on a train announces the last stop to be Centreville, Michigan. Dean decides to go look for Kevin, and Sam tags along. Dean gets back to the Impala and inspects it, they get in and drive away.
At a motel, Dean stands outside a vending machine, an suddenly has a flashback to his time in purgatory. He is being chased by a random monster, after an epic battle with it, he kills it, only to be almost eaten by a second monster. As he is about to die, he is saved by the man we saw resurrected at the start, and the flashback ends.
In their room, Sam tries to explain why he never looked for Dean and why he quit hunting (for a girl and a dog). He presses Dean about his time in purgatory and Dean has a flashback again, where he has a conversation with the man who saved him, who knows a way out of purgatory. On one condition, that he take the man's soul with him so he can be resurrected back on Earth. After some negotiating, Dean agrees if they take Castiel with them. The man agrees. In Centreville, the brothers meet up with Kevin's old girlfriend, who says she had never seen Kevin after the breakup and she only went out with him because he was a nerd. The brothers leave, sidetracked once more. Back in her dorm room, Kevin's girlfriend (Charlene) slits her room mates throat and fills a bowl with the blood. She then has a conversation with Crowley. She reports that Dean is back.
Back to the brothers. Sam has a flashback . He is carrying a wounded dog into a vet's clinic / animal hospital, and gives it to the nurse. He is panicking because he ran it over. The doctor enters and chases him out of the operating room. Flashback Ends.
Dean comes and asks Sam if he made any progress. Sam has backtracked the phone number for the last voicemail to a coffee shop. They are directed to an old abandoned church nearby. When they get there and break in, they are shot at with holy water by Kevin. After proving they aren't demons, they question Kevin about how he escaped Crowley. Kevin has a flashback, in which he is forced to read another Word of God by Crowley. This Word teaches how to open the Gate of Hell in Wisconsin. Kevin reads about a spell, and Crowley and the demons help him to perform it. Dean goes ballistic thinking Kevin really opened a Gate. However, Kevin tricks Crowley, kills his demon minions and escaped with the Word, which also teaches how to banish demons to hell forever. Flashback Ends.
And now Dean and Sam have an argument whether they should get Kevin involved in the banishing. Sam says he should have a choice but Dean disagrees. Sam goes in to talk to Kevin, and has a flashback. He is at the animal hospital. The doctor wants him to take the healed dog, Sam says no and the doctor blasts him and he gives in. She is obviously the girl involved with Sam. Flashback Ends.
An earthquake rocks the building and two demons appear, Sam and Dean beat them senseless, but Crowley and Charlene appear. They order Kevin to give them the Word, or Charlene will die. Since Kevin loves Charlene, he goes to get the Word. When he doesn't return, Crowley and the girl go to investigate. They open a door and are showered in holy water. In the commotion, Sam, Dean and Kevin get into the Impala and drive away. However, Kevin sees Crowley snap Charlene's neck, killing her in punishment.
Later, Dean talks Kevin into joining them, and Kevin agrees. Dean then goes to the bathroom at a gas station, after getting a phone call from a salesman. He doesn't go to the washroom though, instead calling back the number that called him, which turns out to be the man he resurrected. They talk about what happened in Purgatory, and agree not to talk for a while. The End.