Slumber

Daniel Morgan is admitted for an overnight sleep study at the Whittingham Sleep Clinic to monitor parasomnias. He wakes screaming, thrashes, and describes a black shadowy figure with glowing eyes tormenting his room. Dr. Alice Arnolds watches his vitals and EEG, noting the severity of his disturbances as the night unfolds.

During the same night, Charlie enters a deep sleep, convulses, and suddenly attacks Alice with his eyes still shut as if possessed. Staff struggle to subdue him and sedate him, while his EEG flatlines, indicating a severed sense of presence in his body. The moment deepens the clinic's sense of menace.

Alice initially categorizes the events as night terrors or sleepwalking, but the bizarre sequence challenges standard explanations. She notes inconsistencies in Charlie's behavior and the surrounding circumstances, sensing a darker force at work beyond medical science. The night leaves her unsettled about what she can explain with science alone.

Over the next 24 hours, Daniel grows paler and develops deep purple bruises around his chest and neck despite no physical injury. He begins describing the 'dark thing' that now appears in daylight, and Emily reports seeing a tall, skeletal figure in the corners of rooms. The family life is increasingly overshadowed by fear.

Emily begins to perceive the same presence, a hollow-eyed figure that appears in the edges of rooms and vanishes when approached. The phenomenon shifts from Daniel's nights to daytime, intensifying the sense that something malevolent is seeping into the home. The house feels watched and claustrophobic.

Sarah confesses Charlie has become withdrawn and erratic at night, mumbling in his sleep and waking in different parts of the house with bloody fingernails. The home atmosphere darkens as fear tightens its grip on the family. Alice senses the danger may be shared by all in the household.

Alice herself begins to experience waking dreams and paralysis, lying immobile as a monstrous figure climbs onto her chest and hisses in an unknown language. Scratch marks mar her body when she recovers, proving the encounter was real in some sense. The line between dream and reality blurs for her.

Desperate for answers, Alice speaks with Cam, the clinic's janitor, who points her toward Amado, a former sleep expert living off the grid after a mental breakdown. Amado explains the legend of the Nocnitsa, a Night Hag that feeds on fear and invades the subconscious during REM sleep. The folklore provides a possible explanation for the inexplicable events.

Amado expands on the Nocnitsa: an ancient parasitic demon that drains life essence, possesses victims, and spreads trauma through shared dreaming. It targets vulnerable children and those with emotional trauma, feeding on fear. The demon's reach could explain both Daniel's and the family's experiences.

Motivated to stop the demon, Alice decides to induce deep REM sleep and join Daniel in his dream through an experimental technique. She hopes to confront the entity directly and save Daniel from possession. The plan marks a turning point from observation to direct confrontation.

In the shared dream, Daniel's room becomes a nightmarish version of the Morgan house: decaying walls, mangled toys, and rot-soaked corridors. The Nocnitsa appears as a towering eyeless shadow with extendable limbs, looming over Daniel. Alice bravely follows him into the perilous landscape.

The Nocnitsa attacks, twisting Daniel's reality and forcing Alice to relive her brother's death. The creature speaks of blame and attempts to consume her, pressing in with leering hunger. She fights through the horrors, holding onto Daniel's life and her own resolve.

Alice experiences an emotional breakthrough: she accepts that her brother's death was caused by the Nocnitsa, not by her actions. This realization weakens the demon's grip on both her and Daniel and liberates part of his fear. The truth strengthens her resolve to resist.

With the breakthrough, Alice injects Daniel with a stimulant at the exact moment, and the dream shatters—windows explode and monitors blow. She is hurled across the room as alarms scream and reality reasserts itself. Daniel wakes gasping for air, the immediate danger passing.

Daniel's bruises fade and the family breathes a cautious sigh of relief, yet the closing moment shifts to Alice alone in her apartment. The Night Hag's growl echoes, and a freezing sensation seizes her as her eyes open—suggesting the danger has not ended. The film leaves a chilling hint that the Nocnitsa may still pursue her.