While Crowley tries to deal with his mother, Sam and Dean confront Cain over the Mark.
Sam and Dean try to stop a ghost who is taking revenge against a group of college students by killing people through various electronic devices.
The Winchesters are surprised to see a video on the Internet of Charlie torturing a district attorney. Sam and Dean go after her, and discover that she's after the man responsible for the car crash that orphaned her. However, the Charlie they find isn't the Charlie that they expect.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
During a sheriff's retreat, Jody stumbles across murders involving eaten corpses and calls in Sam and Dean. When they arrive, they ask Jody to keep overeager Sheriff Donna Hanscum distracted while they look into the killings.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
Dean learns that Bobby is the beneficiary in an heiress' will. With no monster sighting, the Winchesters go to find out what Bobby received. However, what they find is a murder and a possible husband-and-wife team of killer ghosts... or so they believe.moreless
Sam and Dean investigate the disappearance of a teacher at an all-girls school and discover that the students are putting on a musical based on Chuck Shurley's Supernatural novels based on their lives.moreless
Dean insists on going hunting on what he figures is an easy case: three werewolf-related murders. However, the brothers soon encounter a prior acquaintance and find out that the murders aren't as clear-cut as they seemed.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
Priscilla fights her way back to reality with the help of Aaron and Rachel. Trueman's atrocities escalate as he tries to stop the resistance. Bass and Miles kidnap the President.
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.
With his wife and son now dead, Neville joins with Bass to seek his revenge on the patriots. Rachel finds out about Priscilla, and Miles and Charlie pinch a steam train.
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.
Charlie finds Miles and Truman gets his shot to get Miles and Bass.
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.
Miles gets injured fighting off a bunch of Sheriffs and then gets inadvertently trapped in a dilapidated building making his way back to camp. Tom kidnaps Charlie and discovers the truth about Jason.moreless
In Chicago, Sam and Dean encounter five clans of monsters that run the city's underground... and Ennis, a young would-be hunter who seeks revenge on one of the clans.
Sheriff Mills calls in Sam and Dean when a prisoner under her protection is abducted by vampires.
Metatron tries to get Castiel to join forces with him. Meanwhile, Sam and Dean capture Gadreel.
After receiving inside information from Jason, Miles and Monroe head to Austin to try and sabotage the Patriots' plans. Aaron becomes concerned over Priscilla's odd behavior.
Sam goes to check out a report of peaceful people transforming into violent killers and discovers a connection to a case involving his grandfather. Meanwhile, Dean deals with the aftermaths of acquiring the Mark of Cain and Crowley is eager to take advantage of his weakness.moreless
Monroe makes a jolting attack on the Patriots while Gene and Miles look for potential allies in Willoughby. Neville and Jason find themselves in deep water when Doyle finds out about the poison. Aaron and Priscilla press onward.moreless
Crowley starts taking human blood again and Abaddon learns of his search for the First Blade. To find the Blade before the Knight of Hell does, Sam and Dean enlist the help of a former Man of Letters.moreless
The town of Willoughby has been turned into a reeducation facility, and Doyle makes things difficult for Tom.
Aaron awakes from slumber to find himself back in his previous life, in a world with power. Something however, is not quite right.