|Name||Rebecca "Becky" Warren|
|Location||St. Louis, Missouri|
Rebecca Warren is a friend of Sam's from Stanford. When her brother Zach Warren is charged with murder she decides to take the semester off so that she can be there for him until he is freed. She emails Sam telling him what happened, which leads him into going to St. Louis with Dean to try and help her.
When Sam and Dean arrive at Becky's parents home, she goes into detail about what happened with Zach, claiming he was with her while his girlfriend was being killed. She tells them prior to the murder someone broke into the house and stole some of Zach's clothes and that Zach had begun to act strangely.
Becky soon learns that Sam had lied to her about Dean being a detective after telling Zach's lawyer that she took the Winchesters to the crime scene, and asks Sam to stay out of the investigation. Later that night she is visited by the shapeshifter disguised as Dean, and tells her that it was a shapeshifter that made itself look like Zach and kill his girlfriend. As they are discussing the shapeshifter, "Dean" begins to speak sympathetically about it, and then tries to come on to Becky, who rebukes him and tells him to leave. When she threatens to call the police on "Dean" the shapeshifter walks over to her and throws the phone to the floor. She screams and tries to run away, but he trips her and she falls to the ground. He straddles her legs and begins tying her hands with the telephone cord.
After Sam finds the real Dean and frees him, they plan to meet at Becky's. Dean however decides to go back to the shapeshifters lair, where he finds a beaten and bloody Becky tied to a chair. Dean unties her and they both head back to Becky's where Sam is currently at with the shapeshifter. Once they arrive Dean is able to kill the shapeshifter, and Becky learns the truth about Sam and his "job" as a hunter.