Beth Roberts is a worker for Child Protective Services.
Following the death of her boss, Olivia Sanchez, Beth is given Olivia's office. She is soon visited by Sam and Dean Winchester, posing as FBI agents. Dean remarks the lit candle she put in the room, and Beth explains it is for positive energy, and that she's a Wiccan.
Beth wants to know if Olivia really killed herself as the reports say. Sam reassures her that they're still working on it. He then asks her if Olivia had been acting strange the day before she died. Beth explains that Olivia had "super migraines", but because Olivia was working too hard.
When Sam asks if they had any enemies, Beth tells them receiving threats is part of working in Child Protective Services. Beth hands them Olivia's case files when asked for them. Outside, Dean expresses his belief that Beth killed Olivia out of jealousy, though Sam doubts it.
When a second victim dies in the same manner as Olivia, Dean is able to connect the dots between them. He calls Beth to ask about the Petersons, whom she immediately describes as "weird". She adds that the family is very Old Testament. They even let their daughter Magda die of pneumonia, saying it was God's will.
While talking to the family matriarch, Gail Peterson, Sam and Dean are told that the family liked Olivia more than Beth, because of her religious beliefs. Following the interview, Dean is suspicious of Beth again, and insists on checking her out. He and Sam split paths as a result.
Dean pays Beth a visit while carrying a gun. He asks her if she likes her new job, and is surprised when Beth tells him how much she hates it because of the increase in responsibilities. She adds that no one ever wanted Olivia's job, which leaves Dean feeling flustered and he immediately tucks his gun away.
After Sam solves the case and discovers Magda as an abused child and her mother is arrested, Beth comes to Magda's aid and calls Magda's aunt so Magda can have a home to live in. While Sam sits down with Magda, Beth offers Dean her personal number, much to Sam's confusion. Dean describes Beth as being "kinda hot" for wanting to call him despite the fact that he tried to shoot her earlier.