"Manson's Lost Girls" follows Linda as she first arrives at the seemingly idyllic Spahn Ranch hippie commune where she is embraced with open arms. Seduced by the group's free-love lifestyle, Linda revels in the sisterhood and acceptance. Taken with Manson, he soon draws her into criminal activities, including late-night "creepy crawls" to steal from lavish homes.

Linda reluctantly becomes an accomplice in Manson's "Helter Skelter," a drug-fueled murder spree that included the brutal death of actress Sharon Tate. She ultimately breaks away and turns herself in as a witness for the prosecution and helps to convict Manson.