The demon leaves Sam, Dean, and their father for dead; however, when assistance does arrive, one of the Winchesters is left fighting for his life while the others must face a long-standing foe.
The brothers don't know where the demon that killed their mother is hiding after what happened at the hospital, and they look into murders committed by a killer clown while they wait for inspiration.
When the boys come across a demon hunter slaying a nest of vampires, they learn that evil isn't always black and white.
Dean and Sam look into the death of a young college student who perished in a car accident but whose grave has since grown a circle of withered plants around it.
Sam and Dean come across the lazy slacker with psychic persuasion abilities Andy Gallagher. When the brothers find out that the Demon visited Andy's family, Sam starts to wonder if he might be one of the special kids.
When Sam and Dean look into the murders of blonde women, they discover that the first serial killer's ghost is to blame. Jo disobeys Ellen's instructions and follows them, which leads to her being trapped by the ghost.
Sam and Dean look into the murders of a lawyer and his wife who claimed to have seen a ghost before they passed away; however, before they can locate the ghost, Sam and Dean get detained for double murder.
In order to save Evan Hudson, Dean summons a demon. Dean's worst nightmare about his father is confronted by the demon as they negotiate.
The brothers travel to Oregon in search of answers after Sam sees Dean killing a young man who appears to be under the influence of a demon. Dean reveals what John whispered to him before passing away.
After Dean tells him what their father said before he passed away, Sam snuck away to Indiana without Dean. A psychic tells Sam that she sought him out to forewarn him of his approaching demise.
Sam and Dean look into a town where a number of people have died eerily. The investigation points to a young girl whose imaginary friend may be to blame for the deaths and who, along with her mother, resides at an inn.
Sam and Dean look into robberies where trusted employees rob banks and then kill themselves, but autopsy findings show that the deaths occurred days before the heists.
Sam and Dean look into the killings of a number of people allegedly committed by people who claimed to have been visited by angels and to be carrying out God's will.
Sam calls Dean in a panic after finding him covered in blood and unable to remember what happened to him. When the brothers later come across a tape of Sam killing someone, they get horrified.
The Winchester brothers ask their friend and fellow hunter, Bobby, for help as they look into a string of violent and strange events that occurred on a college campus. When he gets there, he quickly develops suspicions about the likely culprit and observes the brothers' deteriorating conflict.
Sam and Dean attempt to put an angry apparition from a 1992 deadly car accident to rest that is haunting a secluded stretch of highway.
Sam and Dean look into the death of an attorney who was brutally attacked and died. The brothers guard a legal secretary who might be the creature's next victim since they believe a werewolf is to blame.
Sam and Dean attempt to ascertain whether ghosts are to blame for several killings or whether the deaths are a complex deception as they are summoned to a movie set to look into the fatalities.
Sam and Dean look into reports that a ghost is permitting prisoners to be thrown behind bars in a nearby jail, thereby murdering the captives. The brothers discover that it would be harder than they thought to get out of jail when an FBI agent arrives to take over their case.
After being attacked by a Djinn, Dean awakens to a new world in which his mother is still alive and a strange woman is in possession of everything.
The Yellow-Eyed Demon kidnaps Sam and several other special children and transports them to a deserted village, where a decisive conflict must begin.
After suffering a terrible personal tragedy, Dean reaches his lowest point emotionally. A well-thought-out strategic plan is initiated by the Yellow-Eyed Demon to release the forces of Hell.