After her sister’s death, a guilt-ridden teen is sent to a remote mental health rehab center where she navigates tenuous group dynamics and fights to survive a masked killer who’s picking off the kids one by one.

SYNOPSIS:

The story follows Crystal, a troubled teenager grappling with the guilt of a fatal accident that killed her twin sister. In an attempt to help her cope, Crystal's mother sends her to Cliff's Edge, a remote and luxurious teen rehab center nestled in the mountains.

Upon arrival, Crystal encounters a group of fellow patients, each battling their own demons: Maddie, a repeat patient with a history of self-destructive behavior; Dakota, a goth girl struggling with addiction and self-harm; Vince, a quiet and isolated gamer; and Johnny, a volatile and aggressive young man. The center's staff includes the seemingly caring but distant Executive Director, Janet; the empathetic therapist, Lyle; the patient but overwhelmed night staff, Phillip; and the free-spirited art therapist, May.

Crystal's first days at Cliff's Edge are tumultuous. She clashes with her mother during phone calls, struggles to connect with the other patients, and finds the therapy sessions unhelpful. The situation escalates when Crystal's pet tarantula, Elvis, is found murdered, creating an atmosphere of fear and suspicion among the already fragile group.

One stormy night, the situation takes a horrifying turn. Crystal wakes up from a nightmare to find Phillip asleep on the job. While searching for water, she stumbles upon the shocking scene of Janet's murder in her office. The power goes out, and Phillip is brutally killed by a masked figure. The terrified teens realize they are trapped in the center with a killer on the loose.

As the body count rises, the remaining teens - Crystal, Maddie, Dakota, Vince, and Johnny - attempt to escape but find themselves cut off by a locked gate and a pack of coyotes. The group splits up, with some returning to the house while others venture into the dark forest. In the chaos, Vince is drowned in the pool, and Johnny disappears in the woods.

Back in the house, the remaining girls - Crystal, Maddie, Dakota, and Kitty - try to stay awake and alert, but one by one, they succumb to exhaustion. The masked killer returns, paralyzing the girls with a mysterious substance and brutally murdering Dakota and Kitty. Crystal and Maddie narrowly escape thanks to the timely arrival of Logan, a staff member.

As they flee in Logan's car, they encounter Crystal's mother, who has come to check on her daughter after being unable to reach her. A confrontation ensues, revealing deep-seated resentment and blame between Crystal and her mother over the accident. In a shocking twist, Crystal's mother is killed by the masked figure.

Crystal and Maddie escape in Logan's car, but their relief is short-lived as they crash into another vehicle. The masked killer approaches, and Logan attempts to stop them, only to be fatally stabbed. The killer is unmasked, revealing May, the art therapist. May reveals that she was responsible for a similar massacre at the center ten years prior and has returned to finish what she started.

Crystal manages to escape in the car, leaving Maddie behind. As May closes in, Crystal's mother, miraculously alive, rams May with her minivan, seemingly killing her. Crystal and her mother share a tearful embrace, their relationship tentatively mended in the face of unimaginable horror.

One year later, Crystal and her mother are still struggling to navigate their complex relationship, attending family therapy sessions filled with arguments and unresolved trauma.