Sam and Dean investigate an abandoned sanitarium and discover that when the hospital was open, the patients held a revolt against the cruel and unusual punishments inflicted by the head doctor. While the brothers search the premises for four lost college students, the tortured spirits cause them to go insane, turning Dean against Sam.

Dean becomes suspicious of Samuel's motives, but Sam isn't sold on the idea that their grandfather is doing anything wrong. The brothers go along on a hunt with Samuel and the other Campbells, but things go terribly awry.

While searching for a way to defeat Eve, Dean stumbles upon Samuel Colt’s journal in the Campbell library. Realizing Samuel might have the answer to their problems, Sam and Dean ask Castiel to send them back in time so they can meet the man himself. While Sam is a bit reluctant to time travel, Dean is beside himself with excitement to return to the Wild, Wild West.

The broken wall in Sam's head causes him to have hallucinations, and he has difficulty discerning what's real and what's not. Bobby worries that Dean is beginning to stumble under the weight of fighting and keeping an eye on Sam.

Sam, Dean, and Bobby become actual hunters, in the true sense of the word, when they set up camp in a New Jersey state park to track a creature that has been attacking people in the woods. The townsfolk claim it is the real Jersey Devil. Meanwhile, Dean is beyond thrilled to find a Biggerson’s restaurant in town, but is devastated when he discovers the restaurant’s special sandwich seems to be making people crazy.

In order to defeat Dick Roman and the Leviathans, Sam and Dean must locate three key items. Castiel helps with one but for the last objects, the Winchesters must face two of their strongest opponents - an Alpha and Crowley. Meanwhile, Bobby tries out a new ghost trick that ends up being very dangerous.

After Benny gets brutally beat up by some vampires, he calls Dean for help. Dean abruptly packs up and tells a confused Sam that he’s taking a "personal day." Benny confesses that he’s going after his Maker so Dean offers to help, flashing back on the many times Benny helped him and Castiel in Purgatory. Meanwhile, Sam uses his solo time to reflect on the life he left behind with Amelia. However, when things go bad for Dean and Benny, Dean calls Sam for help, which makes everything very complicated.

Sam and Dean respond to a call from Kevin, who is terrified after hearing Crowley's voice in his head. After hearing Kevin's news, Sam and Dean team up with a reaper named Ajay, who helps them deal with the second trial from the Tablet. Meanwhile, Dean receives a visit from Naomi and realizes he must find Benny and ask for a huge favor.

Dean and Sam take a captive Crowley to the Men of Letters base in the hopes that he will give up the names and host bodies of his minion demons. However, they are called away to investigate the disappearance of three soldiers, which leads them to Abaddon, the Knight of Hell... and forces Ezekiel to take control of Sam's body to save his life.

After a suicide angel takes out an ice cream shop to kill one enemy angel, Sam and Dean investigate and discover that the target was one of Metatron's angels... and that Castiel may be responsible. Meanwhile, Metatron tries to consolidate his hold over the angel factions with promises that he will restore them to Heaven.

Castiel finds Jimmy’s daughter Claire in a group home and she convinces him to break her out. After she runs away from him, Castiel calls Sam and Dean to help find her before she gets in trouble. Meanwhile, Crowley faces his biggest challenge yet.