Ruby returns to give Sam and Dean a lead: other demons are searching for an escaped mental patient named Anna Milton (Julie McNiven), who was locked up after she went into hysterics because she heard angels talking in her head about the upcoming Apocalypse and needed to be restrained after trying to warn people. Sam and Dean investigate and find that Ruby was telling the truth and that Anna's claims about the Apocalypse are uncannily accurate. After finding her parents dead at her home, Sam and Dean track Anna to her father's church, where Ruby arrives to warn them that one of the "heavy-hitter" demons looking for Anna has been following them since Anna's house. They are unable to escape before the demon attacks them. It is then revealed that the new demon, whose name is Alastair (Mark Rolston), knows Dean from his time in Hell. While Alastair takes Sam out and beats on Dean, Ruby escapes with Anna. Sam recovers and stabs Alastair with Ruby's knife; while it doesn't kill him, it gives the Winchesters the chance to flee to safety. Believing they were set up by Ruby, Dean lashes out at Sam for trusting her, so Sam tells him what happened during the months Dean was in Hell. Sam's account is depicted in flashbacks; the flashbacks show him encountered Ruby (Anna Williams) again for the first time since Dean's death, while drunk and trying in vain to bring Dean back. Though Ruby had been tortured and eventually released from Hell by Lilith only on the condition that she kill Sam, she had only agreed to it to trick Lilith into setting her free, as she still wanted to help Sam. However, Sam rejected her because she couldn't save Dean from Hell, and demanded that she leave her host body to spare the host. Ruby acquiesced and possessed the body of a brain-dead coma patient (Cortese) whose life support had just been cut so that she would not be usurping someone else's life. She then returned to Sam and he agreed to let her teach him how to use his powers to kill Lilith and avenge Dean. In the meantime, she made him quit drinking and provided him with some physical comfort when she seduced him. She finally earned his trust when she came after him and saved him from a trap Lilith had prepared for him, even though he had threatened to kill her if she tried to intervene. After the last flashback, Ruby briefly takes a different host (Michelle-Hewitt Williams) to find the Winchesters and give them Anna's location. There, Dean extends an olive branch of sorts to Ruby (Cortese) due to his appreciation of how she helped Sam in his absence, and Sam is forced to break the news to a devastated Anna that her parents are dead. The episode ends on a cliffhanger, with Castiel and Uriel appearing and demanding to be taken to Anna so that they can kill her.
Source: Wikipedia
Source: Wikipedia