Lindsey was a woman employed at the bar where Sam worked during a break from hunting.
Lindsey met Sam when he took a job at Hoyt's Bar in Garber, OK. He introduced himself as "Keith".
She quickly developed a liking to Sam, and tried to get him to tell her about his past. Sam was reluctant, and told her that he'd "made some mistakes", and "did some stuff (he's) not so proud of", adding that people got hurt.
She eventually challenged Sam to a game of darts, the prize was sharing life stories over dinner if she won. Sam agreed just to get her off his back, and promptly won the game.
Later, a trio of hunters entered the bar. They recognized Sam, and called him by his real name. When Lindsey tried to question him about it, she was told that "Sam" was his middle name. She made fun of the name "Keith Sam" and asked the men if they were friends of his. Upon finding that they were "old hunting buddies," she needled even further by asking what they hunted. Sam hurriedly took the hunters away to a table, leaving Lindsey suspicious.
Over dinner, Lindsey pointedly asked Sam what was his "poison", saying she could recognize when someone was "hooked". She then produced a sobriety medal and told him she'd been sober for three years. Sam was somewhat shocked that she would work in a bar, until she pointed out that he did, too. She also offered him some unsolicited advice: no one has ever done anything so bad that they can't change and be forgiven.
Later, two of the hunters returned to the bar, and after taking Lindsey hostage, forced Sam to admit that he started the Apocalypse as Lindsey looked on, terrified and confused. They threatened to kill her if Sam didn't drink a vial of demon blood and use his abilities to wipe out the demons that killed their friend. Sam refused, and brutally dispatched the hunters, releasing her.
- In a promo for the episode, Sam is shown having sex with Lindsey, which explains why he is not initially startled when he wakes to see a blonde woman in his bed. Had this scene not been cut, Lindsey would have joined the list of Sam's lovers who did not turn up dead.