DONNA (mid-30s) experiences an erotic dream that becomes macabre when ASMODEUS (40s), a demonic figure, brutally kills her fantasy lover and assaults her. She awakens panic-stricken, but alone. The next morning, she’s is fired from her job because of her chronic tardiness, which exacerbates her psychological stress. During lunch with a former co-worker, BARB (mid-30s) commiserates with her about the termination, and she invites Donna to have dinner with her husband, ALAN (mid-30s) and a co-worker of his, LEON (mid-30s).

Returning to her suburban home, Donna begins to encounter either hallucinations or supernatural visitations from a giant insect, her deceased father, and a revolver, which become progressively horrific and foreshadow either her increasing degree of demonic possession or her deteriorating mental state, or both. Nevertheless, she attempts to maintain a degree of normalcy at Barb’s dinner party, during which she shares the biblical story of Asmodeus, a half-human, half-demon cambion from the mystical Jewish Kabbalah. An argument then ensues when Leon expresses his religious faith and opposition to abortion, which elicits an enraged outburst from Donna who insults everyone at the party before she storms out.

Her final attempt at equanimity occurs at an upscale restaurant in the city, but it ends in failure when she encounters an attractive man, MARK (late-30s) who humiliates her inadvertently. This rejection triggers a animatronic flashback to the traumatic loss of her virginity to EUGENE (late-10s) twenty years earlier. Her psyche spirals further out of control when she kills a neighborhood cat, revealing her growing psychosis.
Months later, Donna hooks up with MIKE (mid-30s) at a sports bar. After she lures him back to her home, she drugs and imprisons him. When Mike regains his consciousness, he’s virtually naked, handcuffed, and wearing a collar that chained to the floor in a soundproof room. When Donna shows him a gruesome video of one of her earlier sexual predations, he realizes that she’s foretelling his gruesome fate.

LIZZIE (early-30s), Mike's fiancée, and ADAM (late-30s), his brother, enlist HILA (mid-50s), a private detective, to find Mike and the enigmatic woman with whom he was last seen. Adam discovers Donna in the city luring another victim, and he trails her to her suburban home. He attempts to search her house, but he’s arrested when a neighbor alerts the police to his intrusion. Lizzie then arrives and pleads with the cops to interrogate Donna and search her house, but when they demur due to the lack of probable cause, she leaves with them as they take Adam into custody.

Hila arrives at Donna's house subsequently and witnesses her watching another video of a murder that she’d committed previously. Assuming that Donna’s kidnapped Mike or Adam, or both, Hila breaks into her house of horrors. As she searches for Donna’s victims, she encounters a life-size sex doll that might be possessed by Asmodeus. Finally, she discovers Donna’s current victim, but Donna kills her before she can free him.

Looking for Hila, Lizzie goes back to Donna’s house and alerts the police to her suspicions again, but when they arrive, they compel her to leave. She does so, but decides to return despite their instructions and stake out Donna’s home until Hila reappears. When she awakens at dawn, she decides to confront Donna. When no one answers Donna’s doorbell, she discovers that the door is unlocked. After hesitating briefly, she decides to investigate on her own, and unwittingly retraces Hila’s steps. She eventually enters the soundproof room and finds the gruesome remnants of Donna's horrific crimes.

While Lizzie’s searching Donna’s house, our antiheroine boards an international flight under a new alias. As it departs, Lizzie calls 911, the police return, investigate the scene and inadvertently trigger a massive explosion from a booby-trap in the basement. During the airplane’s ascent, Donna meets another potential suitor, and they discuss the morality of heroism as she and her murderous muse slip-away to prey again.