Sleepwalker (2017) Spoiler-Free Summary – What It's About

In the wake of a personal tragedy, Sarah Foster finds herself unable to sleep, the night stretching into a relentless void that blurs the line between wakefulness and dream. Desperate for relief, she turns to a specialized sleep clinic, a sterile sanctuary where science and the subconscious intersect. The clinic’s quiet corridors promise answers, but they also whisper of a deeper unease, hinting that the very act of sleeping might pull her into a world where the familiar becomes unsettlingly foreign.

The clinic’s team—led by the composed Dr. Cooper and supported by the methodical Dr. Koslov and the introspective Dr. White—begins to monitor Sarah’s brainwaves, seeking patterns in her fragmented nights. As she settles into a routine of observation, subtle dissonances emerge: names on paperwork shift, a roommate’s presence feels off, and her sense of self flickers like a candle in a draft. The mundane details of daily life start to feel like clues in a puzzle she never asked to solve, and the gentle hum of laboratory equipment becomes a soundtrack to her growing disorientation.

The film unfolds as a psychological thriller that balances clinical precision with atmospheric dread. Every hallway, every whispered conversation, and every fleeting glimpse of a dreamscape is rendered with a muted palette that amplifies the feeling of being caught between two realities. Dawn, Sarah’s roommate, adds a layer of ordinary intimacy that is constantly threatened by the strange, shifting world around them. As Sarah navigates the thin line between treatment and turmoil, the audience is invited to experience the same fragile tension—questioning what is real, what is imagined, and how fragile the mind can be when the night refuses to end.