Following the memories that resurfaced in 6.13 Unforgiven, Sam has collapsed. Dean frantically tries to rouse him while Sam suffers through flashbacks of Hell. He recovers after a few minutes that feel like a week in his mind, and Dean is adamant that Sam take seriously the harm that remembering anything from the last 18 months could do to him. Sam reluctantly agrees. By way of a distraction, Dean has found a case—a janitor named Steve has been found dead in a locked lab at the Great Falls Junior College in Paterson, New Jersey.

The Winchesters investigate the scene but have no leads when a similar incident occurs. A nightwatchman, Dave, dies at the Salzman & Sons Apparel factory in nearby Passaic. Walking around the factory floor, Sam notices the EMF meter detects readings near a mannequin, as it also did near an anatomy dummy at the lab. Sam suggests that a ghost may have possessed the figures, but the boys are confused because ghosts are usually tied to a particular area. Further research reveals that an employee named Rose Brown went missing a year ago.

Dean receives a call from Ben, asking for his help because Lisa is depressed and locked in her room. Sam convinces Dean to go, while he heads off to interview Isabel Brown, the missing woman's sister.

At the Braeden house, when Lisa opens the door dressed for a date, Dean realizes Ben has tricked him. He and Lisa talk, struggling to deal with the fact that despite their feelings for each other, it seems impossible for their relationship to work. Finally, she asks him what he wants, and Dean has no reply. When he talks to Ben, Dean explains that he thinks he is a bad influence and that being in their lives will inevitably lead Ben to a life of hunting. Ben is upset, and charges Dean with abandoning his family. Again, Dean has no reply. As he drives away from their house and back to Sam, Dean remembers the times he's had with Lisa and Ben.

In Passaic, Sam speaks to Isabel Brown. She describes her sister, Rose, as quiet and shy - the sort of girl who was an easy target for teasing and pranks. Leafing through a photo album, Sam realises that the janitor from Paterson also used to work at Salzman & Sons. Back at the factory, Sam interviews workers, and one in particular—Johnny—seems very nervous. That night, Johnny is attacked, but Sam is there to intervene. He confesses to Sam that he and some workmates bullied Rose by leading her to believe she had a secret admirer. When she arrived at an apartment for a supposed date, they revealed the prank, and, as she went to leave, Steve grabbed her and she fell, hitting her head on a coffee table and dying.

Sam finds out where they buried the body and heads off to salt and burn Rose's corpse. He calls Johnny, telling him the haunting is over, but he is mistaken. That night Johnny returns to his apartment and explains to his Real Doll that he is going to leave town, but she becomes animated by Rose's ghost and kills him.

At a loss, Sam speaks to Isabel, and she reveals that she had one of Rose's kidneys transplanted into her when she was 16. As a result, Rose's spirit can move around, able to go wherever Isabel does. Sam drives Isabel to meet with Dean, and the brothers try to figure out a way to put Rose's spirit to rest. Sam suggests Hoodoo as a temporary solution, but, as they discuss the option, the Impala revs up. Rose has possessed the Impala, and she tries to run Dean over. He manages to maneuver it into a wall, but Isabel is fatally injured in the resulting crash. As she dies, the spirit of Rose appears and apologizes before disappearing in flames.

Back at Bobby's place, Dean works on the Impala. When Sam brings him a beer, Dean notes that the case was hardly a victory. Sensing how dispirited Dean is, Sam points out they still save lives now and again. And their luck isn't all bad: they stopped Lucifer, and Dean got Sam's soul back. "Thanks," says Sam. "For what it's worth, I've got your back." And Dean smiles.

Summary from Supernatural Wiki