Kevin wakes up on Garth's boat and checks his board of notes. Someone knocks at the door and Kevin eyes it nervously until Sam and Dean call out. Kevin opens the door and sprays them with holy water, confirming they aren't demons. The Winchesters tell him that they got the other half of the tablet and tell Kevin that he's closest to the end of their quest and seal off Hell. When they ask if they need the other half, Kevin says that they don't need to. Sam tells Kevin to keep working while they draw off the demons, but Kevin is too busy working to notice.
Outside, "Sam" and "Dean" revert to their demon forms and meet with Crowley, who set up the entire fake ship. He's happy to know that there are three trials but warns "Sam" to avoid saying Dean's slang. Crowley tells them to work on their characterizations and dismisses them.
At the Letters' base, Dean brings Sam food but he isn't interested. Sam is running a temperature and hasn't eaten in three days, and he admits that he's not going to be better until he starts the third trial. Dean tells Sam to let him take care of him, but Sam warns his brother that his bad health is part of it all.
Before Dean can respond, they get an email from Kevin with a video attached. They play it and Kevin explains that he left the video to play in case he didn't check in at least once a week. He figures that he's dead and that Crowley got to him. Kevin has uploaded all of his notes and says that the Winchesters have to figure out the rest. He breaks into tears and apologizes for failing at his job, and then signs off. Dean knocks everything off the table in a fit of anger, while the files start printing out.
Dean checks with the Hunters and learns that Garth is MIA. The other Prophets haven't activated, and Dean wonders if they should have moved Kevin there.
In Santa Fe, Castiel is having coffee at a Biggersons Restaurant and chats with the waitress. He admits that he's been on the run for a long time, and the waitress tells him that he'll have to order more than coffee if he wants to stay. Castiel orders the special and the waitress goes off, and the diner starts to shake. He realizes that Naomi's angels are getting closer and teleports away. As a waiter, Perry, tells his boss Tyler that Castiel just disappeared, two angels teleport in and then leave.
One of the angels, Ion, reports to Naomi that Castiel keeps teleporting from Biggersons to Biggersons because there are hundreds of the diners. Naomi says that they'll make Castiel stop.
Sam goes through Kevin's files and recognizes a petroglyph that the angel Metatron left on the tablet. The glyph is a territorial marker for Two Rivers, Colorado that means "Messenger of God," and Sam says that they have to go there. Dean points out that he can barely walk, but Sam insists that they have to go.
Castiel keeps teleporting from Biggersons to Biggersons until he finally stops. The table is covered in blood and everyone is dead except for one waitress. He eyes have been burned out and she tells Castiel that the angels said that he has to stop. Ion and another angel, Esper, teleport in and take him captive.
The Winchesters drive to Colorado and check out the local casino and hotel. They ask the hotel manager clerk for a room and he hesitantly hands over the ledger. Sam hears a chiming sound and asks Dean if he heard it.
Naomi arrives and kills the waitress, and reminds Castiel that God sent them to slew the firstborn in Egypt. When Castiel says that he wasn't there, Naomi says that he was but he doesn't remember it. She tells Castiel that he's the famous spanner in the works who has never done what he was told. When Naomi demands to know where the tablet is, Castiel tells her to bite him. She orders her angels to search all of the Biggersons, figuring that Castiel held the tablet in one of them.
The fake Sam and Dean continue to watch over Kevin as he works on the tablet half. They take his order for food and he tells them that there's a place on the other side of town where they can get Pad Thai. Once they leave, Crowley watches on the monitor and admits that the demons are good actors.
Sam lies down while Dean checks out the hotel and confirms that no one has stayed there since 2006. As Dean sits down, Sam talks about how John took them on a mule trip to the Grand Canyon. He starts laughing hysterically and then says that he'll check out the hotel manager. Dean tells him to get some rest and Sam immediately passes out. Dean finds a local museum and the Indian tour guide explains that the people of the Two Rivers tribe came there many years ago. Their leader told them to stay there because the Great Spirit's messenger dwelt there. They made offerings of stories. Meanwhile, Dean looks at the photos and sees one from a hundred years ago showing the hotel manager.
Sam wakes up and staggers out of his room. As he makes his way down the hallway, he hears a chiming noise. The elevator opens and Sam hastily ducks out of sight and then watches as the hotel manager leaves some packages outside of a door. Once he leaves, Sam checks the boxes and discovers that they contain books of all sorts. He staggers back to his room and calls Dean, but pauses out as he connects.
The angels beat Castiel and report that they can't find the tablet. Naomi says that they want to put the tablet back from where it should be, but Castiel says that he has to protect it from all of them. As she prepares to tear Castiel apart, Crowley teleports in and kills one angel and wounds the other.
Sam wakes up and discovers that Dean has dumped him in a tub of ice water to bring his temperature down. He tells his brother that he's connected to Metatron and that the angel is in the hotel. When Sam mentions the books, Dean realizes that Metatron is still receiving the gift of stories.
Crowley explains that he melted an angel blade down into bullets. Naomi glows with angelic power and Crowley tries to shoot her, but she teleports away. Crowley then greets Castiel and gestures to the wounded angel. He shoots Castiel in the stomach and then tells the traitor angel that he wounded to bring their prisoner along.
Kevin tells the demons that he can't read any further because there's a break and admits that he needs the other half of the tablet after all.
Crowley brings Castiel to his office and the angel says that he won't tell him where he buried the tablet. In response, Crowley says that he won't need to. Thanks to the traitor angel, he knows that Naomi believes that the tablet broke her spell over Castiel. Castiel insists that the tablet wasn't met for the angels and demons, but Crowley figures that Castiel never stopped touching the tablet that freed his mind. He reaches into Castiel's chest and pulls out the tablet half. As Crowley laughs in triumph, the impersonation demons call to tell their superior that Kevin led them into a pre-drawn devil's trap. Crowley tells Ion to watch Castiel while he deals with the situation.
Sam takes Dean to Metatron's room and talks about how he can remember that Dean used to read him stories of knights when they were kids. He realized even then that he wasn't pure because of his demon's blood, but tells Dean that it doesn't matter because the trials are purifying him. They continue to the room and discover that the boxes of books are gone. Dean pushes the door open and they go inside. The room is filled with thousands of books, and a man aiming a shotgun at them.
Dean asks the man if he's Metatron, and the angel teleports behind them and orders them to sit down. Sam continues to hear a ringing noise, and they explain who they are. Metatron asks who they work for and they realize that he's never heard of the Winchesters.
Castiel asks Ion how far things will go before they completely lose their mission, and Ion tells him that the angels like Naomi have been in all of their heads. He insists that nothing matters but Castiel says that it all matters. When Ion looks away, Castiel pulls the bullet out of his chest.
Crowley bursts into Kevin's room and puts the tablet on the table. Kevin explains that he could tell the demons were imposters because they were too polite.
Sam and Dean tell Metatron what has happened to all of the angels, and Sam can barely hear him over the ringing noise. Metatron realizes that he's resonating with the Word or its source--Metatron--because he's undertaken the trials. The angel explains that he worked in the secretarial pool and God had him write down instructions before disappearing. After that, the archangels took over and decided that if they couldn't have God then they'd take over the universe themselves. They needed the Word of God to do that, so Metatron decided to disappear.
Ion talks about how he knew too much but Naomi never fully reset him. Castiel knocks him down and then shoves the bullet into his eyes, killing him.
Metatron explains that he's spent all of his time reading and listening to stories, and he's impressed that humanity has become like gods. Furious, Sam tells him to shoot them because all that Metatron has done is read about the suffering. Dean explains that Kevin became the Prophet and suffered for it, and Metatron never looked out for him.
Kevin boasts that the Winchesters are up to the third trial, and tells Crowley that he has no idea what is on the demon tablet. When Crowley threatens to torture him, Kevin says that they both know that he can't make him talk. Crowley tells Kevin that he has the angel tablet and he's already won, and grabs Kevin by the throat. Kevin's eyes glow and there's a high-pitched noise, and a force of angelic power shoves Crowley back, setting him on fire.
When Kevin appears in the hotel room, Metatron heals him with a touch. He explains that he got past Crowley's ward by erasing it, and has caught up on everything that the angels have done. Dean asks if he's in with them, and Metatron says that it's their choice to close the gates of Hell. However, he warns Dean that they will have to weigh the choice against the cost, and look at what the world will be once it's done. Kevin wakes up and hands them the second half of the tablet. He assures the Winchesters that he didn't tell Crowley, and they wonder what the third trial is. Metatron speaks up and says the third trial is to cure a demon.
As Sam and Dean drive away, they try to work out how to complete the third trial. Sam says that he's feeling better now that they're heading toward the end. They see a figure lying on the road up ahead and Dean brakes to a stop just in time. It's Castiel, who says he could use some help.