In "Bad Day at Black Rock", Bela hires two crooks to steal a cursed rabbit's foot from a storage container owned by deceased hunter John Winchester. Anyone who touches the foot is granted good luck, but will die within a week if the foot is lost. She intends to sell it and shows no concern for the fate of the thieves. John's sons, Sam and Dean, retrieve the foot but are cursed by it. Bela interferes when they attempt to destroy it, and shoots Sam in the shoulder. Dean, however, tricks her into touching it. She gives the foot up for destruction, but manages to steal $46,000 in winning lottery tickets from Dean that he had purchased using the foot's granted luck.
She next appears in "Red Sky at Morning", in which the Winchesters track down a ghost ship responsible for local deaths. Bela fools them into helping her again, with the three of them working together to steal a Hand of Glory, a precious and magical artifact. The Winchesters plan to destroy it in order to end the curse, but Bela steals it from them to sell to a client. However, Bela then witnesses the ghost ship, which only appears to those who have spilled the blood of a family member. Condemned to death, she turns to the Winchesters for help. Dean is prepared to leave her behind to die, but Sam comes up with a plan to save Bela's life. This time, Bela gives them $10,000 as a "thank you" before she leaves because she does not like being indebted to others.
In "Fresh Blood", hunter and recently escaped felon Gordon Walker tracks Bela down and threatens to kill her unless she reveals the location of the Winchesters. Reluctant at first, Bela agrees to do so in exchange for his priceless mojo bag. She then "forgets" to warn the Winchesters that Gordon is coming to kill Sam. Once the brothers later confront her, she uses a Ouija board to obtain information on Gordon and his location.
In "Dream a Little Dream of Me", Bela returns when the Winchesters contact her for help in saving fellow hunter and family friend Bobby Singer after he falls into a mystical coma. They need dream root to enter Bobby's dream and find out what is keeping him asleep. She claims nothing from them in compensation, explains she is helping them in order to repay a debt to Bobby. However, the Winchesters discover after Bobby awakens that she was lying, having helped them to gain access to the Colt, a mystical gun capable of killing any being. Enraged at the theft, Dean and Sam attempt to track her down in "Jus In Bello", but instead are led into a trap she set up; police arrest the Winchesters and throw them in jail. Though the demonic overlord Lilith sends her forces, Sam and Dean eventually make their escape.
In "Time Is On My Side", Dean tracks down Bela and discovers she has sold the Colt. He later gets her criminal record from England and learns her true name is Abbie. Almost ten years prior, when she was 14, she had her parents killed in exchange for her soul as part of a ten-year deal made with a Crossroads Demon. The reason is implied to be abuse by her father. Now desperate because her time is running out, Bela tracks the Winchesters down and tries to kill them, but they had anticipated her and escaped ahead of time. They then call her a few minutes before her deal is up. She confesses to them she tried to get out of the deal with the Crossroads Demon by trading the Colt. Once she gave it up, however, the deal changed so she had to kill Sam as well. She pleads for them to help her, though Dean refuses and mentions she should have asked for help sooner. Bela then reveals to him the demon Lilith holds all the contracts brokered by Crossroads Demons, including his own. At the stroke of midnight, Dean hangs up after saying, "I'll see you in Hell." Her death is inevitable, but not shown.
- Bela was 24 in Time Is on My Side, making her about four years younger than Dean and the same age as Sam.
- Bela is shown to be attracted to Dean in "Red Sky at Morning", when Dean dresses in a tuxedo and asks how he looks. Bela responds by offering to have angry sex with him once the case is solved. They never do, however.
- Dean hinted at some attraction as he was pleased by her reaction to him in a suit.
- Sam is also shown to be attracted to Bela in "Dream A Little Dream Of Me", when he has a dream of nearly sleeping with her, only to be interrupted by Dean.
- Had Lauren Cohan obtained the role of Ruby, as she had originally auditioned for, a love scene between Sam and Bela's actors would've happened.