The In Crowd (2000)

The In Crowd is a 2000 American psycho thriller film directed by Mary Lambert and starring Susan Ward and Lori Heuring. It is about a girl named Adrien who was under psychiatric care. Dr. Thompson helps her get a job at a posh country club. She quickly is befriended by Brittany Foster, the queen of the rich kids who spend their summers there. Adrien learns more about Brittany from various sources and learns that her older sister, Saundra, who looks just like Adrien, had run away two years before. She also learned that Matt, who Brittany is now dating, was Saundra's boyfriend. Brittany's friend Kelly is drowned at sea, by Brittany, when Brittany overhears Kelly hinting at the truth about Saundra to Adrien. When Adrien finds that a shoe belonging to Saundra was found on the golf course, she investigates Brittany, whom she already knows has been lying about various things. She finds that the postcards from Saundra were also a scam that Brittany pulled. Brittany frames Adrien by sleeping with Dr. Thompson while wearing Adrien's dress, getting his DNA on it, then killing him later, making it look like Adrien had slept with him then killed him. Adrien is sent back to psychiatric care. Meanwhile Bobby, another friend of Brittany and Kelly's ex-boyfriend, finds evidence that shows Brittany to be the real killer. He visits Adrien and explains what he found. Adrien manages to escape the psych. unit and lures Brittany out to the golf course where Saundra is buried. Brittany attacks Adrien, and Adrien escapes to find Bobby and tell him what she found. Brittany then explains that she wanted Saundra's boyfriend, and killed Saundra to get her out of the way. The attack ends up in the pool, with all the country club guests running out. Bobby then accuses Brittany of being the killer, and Brittany is unable to lie her way out of her predicament. Final scene shows Brittany in a psychiatric unit, working her charms on one of the men guards.