With the fate of the universe in their hands, Sam, Dean, Castiel, Crowley, and Rowena come up with a desperate plan to kill Amara. However, one of them must sacrifice their existence to do so.moreless
The Winchesters ally with Chuck and Lucifer to destroy Amara, but discover that they need an even greater force to weaken her enough so that Chuck can strike the final blow.
God finally meets with the Winchesters, but he's not what they expected. Meanwhile, Amara requests a meeting with Dean, and the Winchesters set out to rescue Lucifer so that he can help God reimprison God's sister.moreless
While the Castiel-possessing Lucifer tries to take control of Heaven, Sam and Dean hear out Crowley on his plan to stop Amara.
The OSI and the Guild join forces to bring down Blue Morpho, setting a trap for him at the Venture penthouse with the evil Red Death as bait. However, Monarch and Henchman 21 are busy tricking Red Death's wife and daughter into going to his mother-in-law's.moreless
Sam and Dean decide to take a break and check out a wrestling tour. However, when a wrestler turns up dead, the brothers suspect demonic influence. Meanwhile, Crowley escapes from Hell with a little help from a friend and seeks out a weapon to kill Lucifer.moreless
Sam locates an artifact capable of destroying Amara... that was lost at sea in 1943. The brothers convince Castiel--secretly Lucifer--to transport Dean back in time to recover the artifact.
The Winchesters investigate two deaths at a retirement home, where the victims bashed their skulls in because of an intolerable screeching noise. They soon discover that the deaths are connected two deaths that occurred in Ireland 30 years ago. Meanwhile, Lucifer explores the world that he's been reborn into.moreless
While Lucifer tries to convince Sam to let him out of the cage, Dean and Crowley come up with a plan to seal the Devil away permanently. Meanwhile, Castiel joins forces with another angel to confirm if Amara is dead or not.moreless
While Castiel gets a lead on Metatron and interrogates him about the Darkness, Sam and Dean find Amara's location and try to sneak past Crowley's demons to get at the girl and kill her.moreless
The Winchesters decide to take a road trip to get out of the bunker, but find themselves in a life-or-death struggle with creatures intent on raising an army to fight the Darkness.
While Crowley tries to bend Amara to his will, Sam and Dean track down Rowena so that she can undo the attack dog spell that she cast on Castiel... before it kills him.moreless
While Dean delivers Jenna and Amara to Jenna's grandmother, Sam tries to find a cure to the Rabid plague in Superior. Meanwhile, Hannah rescues Castiel from the other angels, and Crowley learns of the Darkness child.moreless
After the Darkness passes them by, Dean begins to remember his encounter with the intelligence at the heart of their new foe. Meanwhile, the Darkness spreads, turning men into killers. Crowley escapes Castiel and makes plans to return to Hell, while Castiel beseeches his fellow angels to help him.moreless
Sam has Castiel convince Crowley to find the three ingredients for the spell necessary to cure Dean of the Mark. Meanwhile, Dean continues to sink deeper under the Mark's influence, and contacts a former ally for help.moreless
While Dean hunts down Charlie's killers, Sam has no choice but to fulfill his end of his bargain with Rowena.
Sam and Dean investigate a woman whose eyes were removed and run into the mysterious Styne family again. Meanwhile, Sam goes behind Dean's back to recruit Charlie and Castiel to help Rowena decipher the Book of the Damned. In Hell, Crowley talks to Olivette and finds a bargaining chip that he can use against his mother.moreless
Claire tries to find her mother Amelia, and Castiel ends up trying to help her... and asks Sam and Dean for help.
Charlie calls Sam and Dean and tells them she found the Book of the Dead that could help remove the Mark of Cain. Unfortunately, a man who claims the book belongs to his family shoots her. Meanwhile, Castiel and Metatron take a road trip to find Castiel's grace, but the journey doesn't go as planned.moreless
While Sam and Castiel free Metatron from Hell, Dean goes out drinking and meets Rowena. Meanwhile, Crowley decides what to about his mother.
While Crowley tries to deal with his mother, Sam and Dean confront Cain over the Mark.
Sam and Castiel turn to Metatron for help trying to cure Dean, while Claire plans revenge against the man who killed her second father. Meanwhile, Rowena continues her plan against her son Crowley.moreless
Castiel turns to Sam and Dean for help, when he tries to help the daughter of the man he's possessing but she escapes. Meanwhile, Crowley and Rowena have a chat, and Dean worries about what will happen if he gives in to the Mark again.moreless
Sam and Dean track down a demon prostitution ring which leads them to the witch Rowena. They go after her, unaware that Cole is still on Dean's trail. Meanwhile, the husband of Hannah's host body comes looking for his wife, complicating things for Hannah and Castiel.moreless
Sam tries to cure Dean and remove his demonic essence, but discovers that his brother doesn't want to be cured. Meanwhile, Crowley realizes that he will need someone to rally the forces of Hell behind to maintain their loyalty, and seeks out a dying Castiel.moreless
Crowley discovers that Dean is becoming increasingly difficult to control, and contacts Sam to make a deal. Meanwhile, Sam escapes from Cole and returns to his hunt for his brother, and Hannah tries to make a deal with Metatron to save Castiel's life.moreless
Dean embraces his new life as a demon and hits the bars with Crowley. Meanwhile, Sam tries to track down his brother, unwilling to accept what Dean has become, and runs afoul of a man trying to get revenge on Dean for a past crime.moreless
Dean falls increasingly under the spell of the First Blade. Meanwhile, Metatron makes his move against humanity, as Sam, Castiel, and Gadreel try to stop him.
Castiel calls on the Winchesters to help when his army of angel followers are attacked, and Dean is all too eager to help under the First Blade's influence.
While Sam and Dean help Castiel interrogate one of Metatron's angels, Abaddon takes extreme measures to force Crowley to help her against the Winchesters.