Kevin is at Garth's ship, trying to sleep, when he hears Crowley's voice in his head. Crowley tells him to give up and knows that he's working with the Winchesters. Kevin tries to find the demon, who says that he's only in Kevin's head, and warns the Prophet that the last time they met, he took Kevin's finger. To demonstrate his power, Crowley makes Kevin hallucinate his arms and legs disappearing.
Sam and Kevin get Kevin's call and come to help him. He tells them what happened and is worried that Crowley knows where he is. The Winchesters assure him that if Crowley knew where Kevin was, he'd already be there. Kevin tells them that he deciphered the second trial and that to pass it, someone must go to Hell, rescue an innocent cell, and take it to Heaven.
To find a way to Hell, Dean and Sam go to a crossroads and perform the ritual to summon a demon. When it arrives, it takes one look at the Winchesters and immediately tries to leave, only to discover that the brothers summoned it within a devil's trap. The brothers take it to a barn and torture it with holy water, and the demon insists that Crowley will kill him if he talks. They continue with the holy water until he breaks and tells them that there is a rogue Reaper who will take people to Heaven or Hell. The demon begs them to kill him rather than leave him to Crowley, and Dean assures him that they will once they're sure the demon has told them everything.
That night, Sam and Dean find the Reaper, Ajay, who works as a taxi driver. They immediately ask him to take them to Hell, and Ajay says that he'll do it if they agree to owe him a future favor. When Ajay addresses them by name, they wonder how he knows them and the Reaper says that everyone knows about the Winchesters... and he was the Reaper who took Bobby to Hell. They wonder why their friend ended up there and Ajay explains that Crowley forced Bobby to reside in Hell. Dean immediately asks Ajay to take two of them there and arrange for three of them to come back. However, Sam warns his brother that he's the only one who can perform the trial. Dean isn't sure that Sam can handle it given his current condition, but Sam promises that he'll find Bobby and bring him back. Ajay tells them that Sam will be back in exactly 24 hours, and Dean should be there then. As Ajay leads Sam into a nearby alley, a homeless man listens to their conversation.
Once they enter the alley, the graffiti to the wall comes to life, revealing a doorway. They step through the portal and Sam is surprised to find himself in Purgatory. Ajay explains that Purgatory is as close as he's going to go to Hell with a Winchester, and tells Sam to be back in 24 hours. As Sam takes out his demon-killing knife, Ajay warns him that Purgatory isn't an easy place and disappears.
Dean returns to the ship with food for Kevin, and the teenager emerges from a closet that he's painted with demon wards. Kevin wants to leave immediately but Dean offers him a burger and tells him to relax. As Kevin eats and says that sealing off Hell is the only way he can get out, Dean tells him that there is no way out for people like them. All they can do is suck it up and push through. Kevin considers it and then takes Dean's pie and goes back in the closet.
When Ajay returns to Earth, he finds Crowley waiting for him in his taxi. Crowley already knows that Ajay is helping the Winchesters and asks for details. Ajay finally admits that he works as a freelancer, and Crowley angrily points out that no one freelances for the Winchesters. The Reaper tells Crowley that Sam will be returning in 17 hours and Crowley, satisfied, kills the Reaper with his celestial blade.
As Sam walks through Purgatory seeking the portal, a monster attacks him. Sam loses his knife in the struggle and decapitates it with its own weapon. He finally finds the portal moves out the boulder blocking it, and is sucked into Hell. He makes his way through the hallways, doing his best to ignore the damned souls begging him for help. Sam finally reaches a cell and opens it, and discovers that Bobby is inside. Bobby sees Sam... and punches him. When Sam wonders what he's doing, Bobby accuses him of being a demon and Sam recites personal facts about Bobby that no one else would know. Convinced, the veteran hunter explains that Crowley has been sending demons disguised as Sam and Dean to torment him. Sam explains why he's there and gives Bobby the demon-killing knife.
Crowley meets with his new assistant demon and tells her that something is going on with Kevin and the tablet. He tells her to find the Prophet and get the half-tablet back, and she eagerly agrees.
Dean is making breakfast and discovers that Kevin is gone. The Prophet comes back and explains that he hid the tablet, and refuses to tell Dean where he hid it. He points out that Dean has no way to force him to tell, and then goes back into his closet. As Dean takes it in, Naomi appears to him and introduces herself. Dean knows what she did to Castiel, but Naomi insist that she's doing whatever she has to so that she can save Earth. Castiel has the half-tablet, but it's too dangerous for any person to hold. The angel insists that she and Dean are both warriors and that she was just following orders. When Dean says that he doesn't trust angels, Naomi points out that the ship isn't warded against angels, and figures that Dean is hoping that Castiel will come back anyway. She suggests that they work together, and as a gesture of trust tells Dean that Ajay took Sam into Purgatory to get him to Hell.
Sam and Bobby head back to the portal, but run across a demon. Bobby kills it and another demon jumps them. By the time Bobby kills it, a third demon has arrived and taken on Sam's shape. The real Sam tells Bobby that he's real, but there's no way to tell them apart. Bobby stabs the demon in the heart, killing it, and Sam wonders how his friend realized which one was real. IN response, Bobby just shrugs and says that it was a 50/50 chance, and they head for the portal.
After 24 hours elapse, Dean goes to meet Ajay, only to discover that he's been murdered.
Sam and Bobby go back to Purgatory, and Bobby isn't happy to learn that they have to go there to get back to Earth.
Dean hesitantly calls Benny and they make small talk for the first time in months. Dean finally braces himself and tells Benny that he needs him to do a favor.
As Sam leads Bobby back to the other portal, he tells his friend what happened. Bobby is eager to go back and help them, but Sam warns him that they burned their bones. Also, Sam has to send Bobby to Heaven in order to complete the trial. Bobby is resigned to his fate and admits that he hoped once he was dead, it would be the end. However, he tells Sam that if he can figure out a way to bring him back, he'll be glad to come. Sam reaches the portal and confirms that it's the proper time, but there's no sign of Ajay.
Benny drives to meet Dean, who tells him what is happening with Sam. Dean needs Benny to go back to Purgatory and bring Sam back, and admits that he'll have to decapitate his friend to send him there. Despite the fact that Dean put an end to their friendship, Benny is eager to help him and admits that he wants a break from Earth. Since his return, he hasn't been able to blend in with either vampires or humans, and he's starting to feel the strain. Dean promises that he'll help Benny when he gets back, and tells him to ride back with Sam the way he came back with Dean. Benny tells him to get on with it and they share a hug, and then Dean decapitates his friend.
As they try to come up with a plan, Bobby asks about Dean's time in Purgatory and realizes that Sam didn't try to bring Dean back. Sam points out that they had an agreement to not risk their lives trying to save the other, but Bobby says that it's a non-agreement. More monsters emerge from the forest and attack them, and Benny arrives in time to help them. Bobby is ready to kill Benny when he realizes that their rescuer is a vampire, but Sam holds him back and explains that Dean must have sent Benny. Bobby, shocked, figures that the Winchesters must have lost it since he died.
Dean drives away toward Maine, the spot where he emerged the last time, and Crowley's homeless demon watches him go.
As Benny leads Sam and Bobby to the portal he uses, he explains that he's a disgrace to vampires and they can't tolerate him. They reach the portal and Sam and Bobby say their goodbyes. However, Bobby figures that they'll see each other again someday. The two men cut their arms and share blood, and Bobby enters Sam's body. As Sam prepares to do the same for Benny, three vampires emerge from the forest and advance on them. Smiling, Benny tells Sam to tell Dean that he said goodbye. As he prepares to sacrifice himself as bait, Sam tosses him the stolen weapon and goes to the portal. As he goes through, Sam turns back and sees the vampires tearing Benny apart.
Dean arrives at the portal in Maine and watches as Sam comes through. They embrace and Sam explains that he was wrong about Benny, who sacrificed himself to save them. When Sam figures that Benny wouldn't have come back anyway, Dean agrees. Sam cuts open his arm and performs the ritual, and Bobby's soul floats up toward Heaven... and stops. Crowley materializes and tells them that as the King of Hell, he won't let Bobby escape. The Winchesters try to attack him but he easily stops them and prepares to send Bobby's soul back to Hell. However, Naomi appears and stops him. When Crowley warns her that the Winchesters plan to seal off Heaven and Hell from Earth, Naomi says that she'll be glad to help them seal off Hell and deal with the rest later. Disgusted, Crowley teleports away and Naomi sends Bobby's soul on to Heaven. She then turns to Dean and smugly tells him that he can trust her, just like she said earlier. Once she teleports away, Sam completes the trial and screams in pain as his arm glows briefly with a golden light.
Kevin is at the ship putting up more wards when the ship starts to shake. The windows shatter and Crowley teleports in. He explains that they tortured Kevin's mother to find out his location. When she didn't break, they simply killed her and got Kevin's phone number from her smartphone. As Kevin screams in anguish, Crowley tells the Prophet that as the King of Hell, he is forever and ultimately there is nothing they can do against him.
As Sam and Dean drives back, Dean tells his brother that he didn't burn Benny's bones because he still hopes that Benny can find a way back. Sam admits that Benny wasn't what he expected and agrees with Dean's decision. When they get to the ship, they discover that Kevin is gone, and all of his notes with him. Unaware of the truth, Dean figures that Kevin freaked out and went to ground, leaving them with no way to find him.