Kevin Trans is playing his cello at home.
South Chicago, Illinois
Sam and Dean set up in an abandoned building.
When Kevin's scheduled practice is complete, he gets a phone call from Channing. They discuss his college essay and he admits that he doesn't have anything to say. Channing assures him that college won't matter one day, but he doesn't believe it.
The brothers chip open the piece of clay that they stole from Dick Roman. After hitting it for the first time, a storm starts up outside. They figure that it's some kind of warning but Dean has no choice but to continue. They finally break it open and find a black stone tablet with writing inside.
At home, Kevin hears the storm build outside and suddenly lightning slams down through the ceiling, hitting him and lifting him into the air. It stops and he collapses, his eyes glowing.
At the hospital, Meg is watching over the insane Castiel and is surprised when he suddenly sits up.
At the Leviathan site in Wisconsin, Edgar is putting together the assembly line for humans when he gets a call from Dick Roman.
The next morning, Kevin wakes up when his mother calls. He realizes he's late for his test, but as he leaves he starts to have visions.
Dean wakes up and finds Sam working and listening to a radio about the mystery storms. Sam confirms that Bobby is there but low on energy, and tells Dean that every woman in the last month of her pregnancy went into labor when they cracked upon the clay to find the tablet inside. He hasn't had any luck identifying the writing, and Dean wonders why Dick wants. Sam suggests they hole up at Rufus' cabin and Dean agrees. However, Meg calls to tell Sam that Castiel woke up the previous night, and explains that she's been busy with him ever since. She refuses to answer more questions and tells them to come see. The brothers realize that Sam revived at the same time that they freed the tablet.
That night, Kevin is driving when Channing calls and asks why he wasn't at school. His eyes glow and he tells Channing that he's been chosen, and that he's taken his mother's car and is supposed to keep going. He ignores her questions and keeps driving.
The Winchesters arrive at the hospital and an orderly, Abel, tries to stop them. Meg says that she's been expecting them and escort the brothers in to Castiel's room. He greets them, seemingly normal, but then asks Dean to pull his finger. Dean reluctantly does so, there's a flash of lightning, and the lights explode. Castiel chuckles and starts talking about how he can see the whole route of nature. He rambles on about how beautiful Meg is and then explains that a "ping" pierced him, a ping that only angels can hear him. Sam shows him the tablet and Castiel says that the Winchesters were the ones to free the Word from the earth, written by the angel Metatron, the scribe of God. He can't read it and Meg asks to read it, but Dean refuses. When they argue, Castiel says that he doesn't like conflict and teleports away, dropping the Word. Dean goes to get him while Sam refuses to answer Meg's questions. She walks away, explaining that Castiel has a crush on her and will follow her. They hear a noise and go back to the room, and discover that the Word is gone.
Kevin runs across the grounds, carrying the Word. Sam chases him and Meg finally gets ahead of the student and knocks him down. He begs them not to kill him and explains that he can't let go of the Word.
Dean points out that Castiel just broke God's Word, and realizes that he's just seeing a different side of Sam's insanity. Castiel speaks vaguely of what brought him there and tells Dean that he has different answers than Dean wants. When Dean asks if he remembers what he did, Castiel gestures and sets up a game of Sorry! with a glance, and asks if Dean wants to go first.
Sam and Meg bring Kevin back to the room and he says that he knows that he's supposed to keep it even though he doesn't know what it is. After a moment, Sam tells him to open it and Kevin does so. When he touches two of the pieces together, they assemble themselves.
As they play, Castiel talks about the birth of humanity and ignores Dean's questions about where they can find Metatron. The angel merely says that the universe is designed to create conflict and that he can't break the rules. Dean reminds him that he tried to change some rules when he became God, but Castiel just tells him that it's his move. Frustrated, Dean sweeps the board to the floor and tells Castiel that he's not sorry, he's just playing the game.
Kevin is able to read the tablet but admits that it hurts. He tells Sam that it's about the origin of Leviathan and how God locked them up far away. Kevin realizes that they're real, and warns that he has trouble reading. The lights flicker and Meg warns that someone is coming. Two angels arrival and slam Meg into the wall.
Castiel tells Dean that Kevin is talking to angels.
The angels tell Dean to step away from the prophet, the sole keeper of the Word. Their leader Hester tells her minion Inias to take Kevin, but Meg slashes his hand with a demon blade. Before they can break the standoff, Castiel teleports in. Inias is impressed, but Hester tells Castiel that he disappeared on them. When they wonder where he's been, Castiel says that he doesn't have all the answers but can offer perspective. When he invites them to pull his finger, Hester stares at him in shock and realizes that he's insane.
Dean arrives and uses a blood sigil to send all three angels away. As Sam demands to know where Meg got the angel-killing knife, Sam explains to his brother who Kevin is. The Winchesters bring him up to speed and Kevin explains that the Word is some kind of message. When he reveals that he's a prophet, Dean warns that he doesn't want to be one. Meg suggests that they get out before the angels return and Dean reluctantly agrees.
The Winchesters and Meg drive Kevin toward the cabin. They stop at a gas station and Dean fills the tank while Sam and Meg try to avoid each other. Sam catches a news report on Kevin's abduction, attributing it to a cult. Outside, Meg sees two demons watching her. As Sam tells Dean about the newscast, Meg arrives and insists that everything is fine.
That night, Kevin realizes what is going on with his life and starts to panic. Castiel calls Meg and starts talking about how he's in Perth, Sydney. Meg gives him directions and he instantly teleports into the car, startling Kevin. Meg introduces Castiel to Kevin, and Castiel explains that the two angels were from his old garrison and he was their captain. He finally explains that when the Word of God is revealed, a keeper is chosen at the same time. Garrison code dictates that the angels take the keeper to the desert so he can learn the Word. Castiel warns that if they want the Word then they'll have to duck Hester and her soldiers, and that he won't fight anymore.
At the cabin, Sam paints the walls with angel-invisibility sigils, but can't put up the repulsion ones with effecting Castiel. Dean takes Kevin to the basement and tells him to start translating the Word. Sam asks Castiel if he sees Lucifer and the angel says that he did at first, but says that it was a projection of Sam's. Now he sees everything, and was lost until he took on Sam's pain. It gave him a focus and Sam thanks him for his help. He promises Castiel that they'll help him get better, but Castiel doesn't know what he means.
Kevin starts translating the Word and has another painful seizure. He panics again, unable to process the existence of the supernatural, and Dean has him breathe into a paper bag until he gets control of himself. All Dean can tell him is that he's been chosen and it sucks, and the angels don't care because they can't. Kevin says that he just wants to be President and Dean tells him to do his homework.
Meg goes outside as the two demons from earlier arrive in a semi. She told them earlier that she has something for Crowley, but the demons warn that Winchesters are old news. When Meg tells them that she has Castiel, the demons don't believe it and assure her that they didn't tell anyone. They try to attack her and she kills both of them with the knife and then goes back to the cabin. However, she discovers that the Winchesters have set a devil's trap for them. They take the knife and Meg says that she killed demons on their behalf. Castiel confirms that she's telling the truth, and Meg explains that when Lucifer and the Yellow-Eyed Demon were destroyed, she found a new cause: bringing down Crowley. She insists that he's ultimately more dangerous than the Leviathans, and doesn't care about hurting Sam and Dean.
Sam breaks the trap and Castiel warns that when Meg killed the demons, she alerted the angels. Hester and Inias break in and accuse Castiel of having fallen. Inias grabs Kevin and Dean says that they're trying to clean up Castiel's mess. Hester, furious, says that Castiel was lost when he touched Dean. She advances on Dean but Castiel tries to stop her. She knocks Castiel down and starts beating him, and then prepares to kill him. Inias tries to stop her but she knocks him back as well. As she raises the knife to deliver the death blow, Meg kills her and shrugs, saying someone had to.
Later, Inias asks Castiel to come with them, but the angel says that he's not part of the garrison anymore. Kevin finishes translating the Word and gives the notebook to Sam. Inias sends his two angels to return Kevin home to watch over him, and Dean tells the others that Meg slipped away and went into hiding. Sam goes over Kevin's notes and confirms that Leviathan can only be killed by the bone of a righteous mortal, washed in the blood of a fallen angel. Castiel gives them a vial of his blood and then admits that he has no idea what he's going to do next. He teleports away and the brothers go to work.
Detective Collins goes to the Tran home and tries to reassure Mrs. Tran. Two of the angels arrive with Kevin and his mother embraces him. She wonders who Inias and the others are, and Kevin assures them that they're protecting him. Collins steps forward and kills the two angels, and reveals that he's a shape-shifted Edgar.