A Serial Killer’s Guide to Life

Lou Farnt is a meek young Englishwoman living with a harsh, emotionally abusive mother. She longs for something better and begins following self-help gurus, especially Chuck Knoah, hoping to gain confidence and agency.

At a self-help lecture, Lou notices a middle-aged woman who exudes charisma and promise. She later learns this woman is Val Stone, who seems to embody the path to transformation. The encounter plants the seed of a potential mentor-student relationship.

Val invites Lou to visit her at a caravan park for a research-focused journey into various gurus. Lou is flattered by the invitation but hesitant to leave home for an extended time. Her mother's emotional abuse pushes her toward the chance to feel independent.

The next day, Lou leaves with Val in a car, beginning a tour of self-help gurus. They plan to observe and report on the ideas they've encountered, as Lou seeks personal growth and a sense of purpose. The trip marks Lou's tentative break from her former life.

Their first stop is a wilderness retreat led by Ben. They participate in activities like tree hugging, pitching camping tests, and listening to an attendee sing in Welsh. The retreat promises communal bonding and transformational experiences.

The next morning, Val hurries Lou to leave the retreat. After they depart, the bodies of Ben and the other attendees are shown, their heads bashed in. The scene reveals the brutal danger lurking behind the self-help world.

The next stop is a 'sonic vibration' retreat run by a husband-and-wife team. The wife is stabbed to death in front of Lou, who witnesses the aftermath. The husband tries to escape as Val overpowers him, and Lou ultimately kills the husband.

Val and Lou leave in the couple's minivan after the murders. Radio news reports the ongoing string of killings as the two lie in wait. In a field, Val pressures Lou to kill her, but Lou resists and the two end up exhausted from their struggle.

They attend a laugh-therapy workshop and murder the members there, adding to their escalating spree. The violence becomes a disturbing pattern as they move from one encounter to another. The thrill of control feeds their dangerous dynamic.

During a visit to a birth-memory guru, Lou begins to hallucinate. She remembers a memory of herself killing her mother, intercut with Val murdering her own mother. The visions blur the line between inner trauma and the murders they commit.

The two reach Chuck Knoah's estate, where Knoah is a pathetic wreck due to divorce and looming publisher trouble for lacking new book ideas. He notes that their memoirs would sell and is on a phone call arranging a meeting with his publisher.

Val shoots Knoah in the head as Lou processes the moment. Lou stabs Val, who had earlier attempted to frame her by calling the police. The two struggle on the edge of a cliff as police and a helicopter close in.

With police arriving, Val seems to vanish as the standoff ends in a dark quiet. The film closes by repeating the opening scene, with Lou walking outdoors wearing earbuds and listening to a Knoah lecture, suggesting a cyclical trap of self-help and manipulation.