Ruby

Ruby believes Nicky has returned because the murders at the drive-in mirror the way he was killed sixteen years earlier. When Louie is found hanged in the woods, Ruby recognizes the same method used to execute Nicky in 1935. Additionally, she hears Nicky's voice calling her name over the theater's sound system and sees violent apparitions that resemble him, leading her to conclude that his spirit has come back to torment her.

Nicky Rocco was betrayed and executed in the swampy backwoods of Florida in 1935 while his pregnant lover Ruby watched. He was killed by other mobsters who turned against him. With his dying breath, Nicky swore vengeance, vowing to return. His spirit apparently returns in 1951 to punish those he blames for his death, including Ruby, who he believes betrayed him.

Leslie becomes possessed by Nicky's spirit, which allows her to speak in his voice. During a confrontation in the attic, Leslie begins speaking as Nicky, revealing that the vengeful spirit has taken control of Ruby's mute daughter. This possession represents Nicky's ultimate means of reaching Ruby through her own child.

Jake Miller was a blind, wheelchair-bound former mobster who lived with Ruby. Ruby herself cut out his eyes and preserved them in a jar, which she reveals to Dr. Keller as proof of her dedication to Nicky. This disturbing act demonstrates Ruby's extreme loyalty to her dead lover and explains why Jake is blind. She later kills him when he appears stabbed to death, possibly by Nicky's spirit.

Ruby walks willingly into the swamp water hand-in-hand with Nicky because she cannot escape his supernatural hold over her. Despite knowing he intends to kill her, Ruby's deep connection to Nicky and perhaps her guilt over his death make her unable to resist. She is dragged underwater to her death by Nicky's skeleton, fulfilling his vow of vengeance from beyond the grave.

Ruby was present when Nicky was executed in 1935 and watched him die. While she admits to having set up other mobsters in the past, she claims she was not responsible for Nicky's death. However, Nicky clearly blames her, possibly believing she betrayed him. Ruby has spent sixteen years living with the guilt and consequences of that night, which is why his return terrifies her so deeply.

The supernatural killings are caused by Nicky's vengeful spirit returning to the living world. Dr. Keller, a clairvoyant prison psychologist, senses a supernatural presence stalking the drive-in property. The killings begin after Jess Littinger experiences poltergeist activity in the projection booth and is found hanged, followed by Louie's similar death in the woods. Nicky's spirit is targeting those connected to his death and Ruby's life.

Leslie has been mute since birth, which is why she cannot speak. However, when possessed by Nicky's spirit, she suddenly speaks in his voice, making her muteness even more unsettling. This contrast highlights the supernatural nature of the possession, as the mute daughter becomes a vessel for her father's rage.

During Dr. Keller's hypnosis session with Leslie, bullet holes mysteriously appear in her head, matching the wounds Nicky suffered when he was executed. This phenomenon proves that Nicky is literally possessing Leslie, transferring his physical wounds onto her body. It also confirms that Nicky's spirit is not just haunting the location but is actively using Leslie as a conduit for his vengeance.

Ruby reveals the jar containing Jake's preserved eyeballs to demonstrate her unwavering devotion to Nicky. By showing Dr. Keller this disturbing proof of her dedication, Ruby intends to prove she is faithful to Nicky despite having lived with other men for sixteen years. This act also reveals the depths of her obsession and the violent history between her and the mobsters in her life.