At the end of the Leviathan War, the demon Crowley kidnaps the Prophet Kevin Tran in order to get him to translate the Demon Tablet for him. However, Kevin kills his guards and escapes with the demon tablet. Subsequently, Crowley chases after Kevin in order to reacquire him and the demon tablet. A year after Kevin's escape, Crowley is able to steal the demon tablet back and Kevin goes on the run with his mother after Dean nearly kills her in an attempt to kill Crowley. At some point around this time, Crowley also captures the angel Samandriel.
In an attempt to translate the Demon Tablet, Crowley tortures the captured angel Samandriel for the names of all the future Prophets so he can kidnap them in an attempt to have the future Prophets translate the demon tablet. After extensive torture, Samandriel finally gives up the names and Crowley sends out his demons to kidnap them. Due to the future Prophets being the vessels of God's Word, each of their kidnappings causes freak weather phenomenon as omens. One of the future Prophets who is kidnapped is Aaron Webber, a preschool age boy whose teacher is possessed and whose kidnapping causes a freak tornado at his preschool that lasts about 20 seconds before the weather returns to normal.
At Rufus's Cabin, Sam notices the omens connected to the mysterious disappearances, but can't figure out how all the people are connected as they are from different towns, religions and age groups. Though confused, Sam and Dean decide to investigate.
At Crowley's factory base in Atlantic, Iowa, Crowley continues to torture Samandriel for more names until Samandriel reveals that there are no more as the next generation of future Prophets hasn't been born yet. Crowley stops the torture and goes into the room where he's holding the future Prophets and brings the Demon Tablet before them.
At the same time, Linda Tran decides to stop hiding from Crowley and to fight back. When her son Kevin returns, she reveals to him that she has hired a witch named Delta Mandotta through Craig's List to gather the ingredients they need for the demon bomb Kevin used to kill his demon guards and escape. Though Kevin is reluctant, Linda contacts Delta who she hasn't given much information to about the bombs beyond what they need for ingredients. Delta promises them that she has gathered almost all of the ingredients that they will need.
Starting their investigation, the Winchesters visit Aaron Webber's teacher, Ms. Hagar who, after the kidnapping, woke up in a park three blocks from the preschool. Ms. Hagar makes no reaction to Sam performing an exorcism discreetly, proving that she is no longer possessed. However, she does admit to smelling sulphur after she woke up, confirming that a demon did kidnap Aaron and possess her.
The next morning, Crowley approaches the future Prophets and asks if any of them can read the Demon Tablet. The future Prophets demand to know where they are and believe that Crowley is an alien who has abducted them. Crowley is astonished at their stupidity and when Dennis starts demanding his rights, causes Dennis to cough up blood and die. Taking the Demon Tablet, Krista reads what she claims is on it but in fact recites the beginning of the Declaration of Independence. Unimpressed, Crowley turns the tablet right side-up and is frustrated by the future Prophets' lack of ability to read it.
At the Tran's hideout, Delta arrives and gives Linda a bag of ingredients. However, Delta has only brought enough for one bomb until she is paid and heads to the bathroom to clean up. Unknown to the Tran's, Delta has betrayed them to Crowley and uses the opportunity to break the salt line in the backroom so that demons can enter. When Delta continues to refuse to give them more ingredients until she is paid, Linda sends Kevin to get her purse where he discovers the broken salt line. Crowley arrives with a demon minion and explains Delta betrayed them as she felt she had more to gain by negotiating with Crowley. After making Delta disappear, Crowley orders his minion to kill Linda and destroy the demon bomb ingredients before teleporting away with Kevin. The demon advances on Linda, but she grabs a squirt gun full of holy water and blasts him in the face, causing the demon intense pain. Linda is ultimately able to subdue and capture the demon.
Sam continues to track the disappearances, noticing Luigi's in Rome, but they eventually stop when Crowley has all of the future Prophets and Sam is unable to find a link between them. Sam starts listing the names of the kidnapped people to Dean and both are surprised when Castiel finishes the list. Castiel explains how the people who have been kidnapped are all future Prophets, one of whom will be called if Kevin dies. The Winchesters realize that Crowley has kidnapped the future Prophets as insurance before getting a call from Linda letting them know of Kevin's kidnapping. The Winchesters set up a meeting point with Linda in order to find and rescue Kevin and the missing future Prophets.
Crowley takes Kevin to his base and tells him that now that he has captured all of the future Prophets, if Kevin refuses to read the tablet for him, he will simply kill him and one of the future Prophets will take Kevin's place and read it instead. Kevin, believing that Crowley has killed his mother and will kill him afterwards, refuses. Though Crowley is willing to kill Kevin and have someone else read the tablet, he is unimpressed with the future Prophets and would rather force Kevin to do his bidding. To demonstrate how serious he is, Crowley raises Krista into the air and causes her to explode in a shower of blood and gore. He then asks Kevin if he's read any good tablets lately, trying to use Krista's death to force Kevin's cooperation.
At the meeting point, Linda arrives and explains that she hired a witch to help them make demon bombs and the witch ratted them out. Linda brings with her the ingredients for the demon bomb Delta had given her and Kevin's notes on how to create them. Dean asks if Linda has any idea where Crowley took Kevin, but while she doesn't, she shows them the demon she captured held under a devil's trap in the trunk of her car. Dean draws the demon-killing knife and demands answers from the demon who eventually gives up the location of Crowley's base in Atlantic, Iowa where he's holding Kevin and the future Prophets.
Since Kevin continues to refuse to cooperate, Crowley takes him to the chamber where he had been torturing Samandriel and demands that Kevin read the tablet for him. When Kevin remains silent, Crowley grabs a knife and cuts off Kevin's left pinky finger, causing Kevin to finally give in. Kevin begins reading the headings of the different tablet sections to Crowley who is unimpressed and demands that Kevin find him something "game changing." Continuing to read, Kevin finds the section on closing the Gates of Hell forever, causing Crowley to realize that it truly can be done and the Demon Tablet must be kept out of human hands. Kevin eventually finds something different, a "farewell note" from the Scribe of God Metatron. The note reveals that there are a compendium of tablets, causing Crowley to realize that more tablets exist than just the Leviathan and Demon Tablets.
Having gotten the location of Crowley's base from the demon Linda captured, the Winchesters, Castiel and Linda travel to it where Dean checks with the captured demon that its the correct location. After confirming it, Dean kills the demon while Sam handcuffs Linda to her steering wheel so she won't attempt to follow them inside and possibly get caught and taken as a hostage. Sneaking around the outside of the factory where Crowley's base is kept, the Winchesters and Castiel spot a demon guard. Dean sneaks up behind the guard and kills him with the demon-killing knife. Sam then heads off in a different direction than Castiel and Dean to search.
As Sam makes his way through the base, he spots four demon guards in a big open area. Sam enters and pretends to be surprised to see the demons who advance on him, believing they have the upper hand. Sam throws the demon bomb the Winchesters had made with the ingredients Kevin and Linda had gotten from Delta, vaporizing the four demons and leaving their shadows imprinted upon the wall behind them. Sam then locates the room holding the five surviving future Prophets nearby and rescues them.
Dean and Castiel make their way through another area of the base where Castiel senses Kevin to be close. As they approach the room holding Kevin, the two are assaulted by a final demon guard who telekinetically throws Dean into a row of hanging chains. The demon is able to keep Castiel back with his telekinesis momentarily due to the Seraph's weakened state, but Castiel quickly breaks through and smites the demon. However, smiting the demon causes Castiel to nearly collapse. Reaching the door, Dean begins attempting to pick the lock before Castiel tells Dean that he is going in on his own.
As Crowley realizes there are more tablets out there, Castiel teleports into the room, surprising Crowley who had believed him to still be in Purgatory. Castiel tells Crowley that Kevin is coming with him and draws his angel blade when Crowley refuses to let Kevin go. Crowley draws one of his own, believing that Castiel is too weak to fight him. Castiel prepares to blast Crowley with white light, displaying his wings in a show of intimidation as he does so. While at first Crowley believes Castiel to be bluffing, he quickly realizes that he isn't and grabs the Demon Tablet. As Crowley lifts it off the table, Castiel smashes the tablet and table with his elbow, destroying the table and breaking the Demon Tablet into two pieces. Crowley quickly teleports away with the half of the Demon Tablet he was holding when Castiel smashed it, leaving the other half behind for the Winchesters. Moments later, Dean breaks into the room to find Kevin with half of the Demon Tablet, Crowley gone and Castiel collapsed from the effort he had expended.
With the demons gone, the Winchesters call the police who pick up the future Prophets and return them home. Sam informs Kevin and Linda of this as well as the fact that they have called Garth to look after them. Sam chides Linda for calling a witch which had caused them to get into trouble in the first place and Kevin is more determined than ever to seal the Gates of Hell forever.
While Sam talks with the Tran's, Castiel shows Dean the truth of how he got left behind in Purgatory. He is then taken to Heaven in secret by Naomi who explains that the angels rescued Castiel and forces him to report on the situation. Naomi then orders Castiel to remain with the Winchesters and help them in their search for the second half of the Demon Tablet which Castiel agrees to do when Sam requests it upon his return to Earth. Due to Naomi's control over him, Castiel retains no memory of the meeting or her orders.
With half of the Demon Tablet now in his possession, Kevin, hidden in Garth's houseboat, sets to work on translating it. He is eventually able to locate the first two Trials of God that will seal the Gates of Hell forever. When Metatron rescues him from being kidnapped by Crowley yet again, Kevin is able to retrieve the second half of the Demon Tablet and with it, the Third Trial. The Demon Tablet is eventually repaired when Crowley demands it as part of a deal that the Winchesters use a trap for him.
- Sam tells Kevin that Castiel believes he can fix Kevin's cut-off finger. Though its not shown on-screen, later episodes confirm that Castiel did fix Kevin's missing finger.
- In Season 11's All in the Family its revealed that there was a future Prophet that Crowley missed, Donatello Redfield. In Season 14's Prophet and Loss, another Prophet named Tony Alvarez is introduced. Like Donatello, he was not one of the future Prophets named or kidnapped by Crowley.
- This battle marks the first use of an angel blade against a demon when Castiel draws his against Crowley. It is later confirmed that angel blades can in fact kill demons.
- When talking with Aaron Webber's teacher, Sam calls her Ms. Hager despite the fact that a news article lists her name as Ms. Van Nest. Also, she gives Aaron's age as five when his missing person's report and the same article gives his age as four.