Gloria, Nina Kiri, is kidnapped by a cult that gathers under a looming locust moon, staging a chilling occult ritual behind grotesque masks before sealing the night with suicide. Five years pass, and a traumatized Gloria lives with her mother Ruth, Nina Richmond, slowly learning to cope with what she endured while the memory of that night lingers like a bruise she can’t quite shake.
She begins attending a therapy group at her local church, accompanied by her lover Joan, Jorja Cadence, who hints that she has something special planned for their anniversary the next day. The tension tightens as Gloria’s fragile sense of safety keeps slipping away, and the shadow of the past creeps closer to the present.
Then Gloria is kidnapped again, this time by Thomas, Ry Barrett, a man whose face is hideously scarred by fire, and he takes her to a remote cabin in the countryside. Joan launches an increasingly frenetic search for Gloria, even threatening a man with a knife when he seems indifferent to the disappearance. A police officer learns of Joan’s violent behavior and suspects she was involved, which leads Joan to kill both him and the inconvenient witness Ruth, severing any chance of a straightforward rescue.
Thomas explains that he was one of the cultists five years ago, and that he faked his suicide to protect Gloria from the remaining members who intend to finish the ritual under the coming locust moon. The cultists believe they have implanted the demon Abaddon, the “Taker of Souls,” within Gloria, and that it has been growing inside her for years. As the moon rises, Gloria’s health deteriorates and visions of Abaddon intensify, while strange, malevolent phenomena fill the cabin. The transformation is physical as well as mental: Gloria begins to grow wings, and Thomas comes to fear that she is truly becoming Abaddon, even contemplating killing her to end the horror before it’s too late.
The truth about the cult’s leadership finally comes to light: Joan is the mastermind, but Thomas reveals that Joan is actually his sadistic sister Gwendolyn, who scarred him with fire. Gloria’s metamorphosis continues, and she starts speaking in the voice of Abaddon, declaring that she will kill Thomas first and claim his soul for hell. Gwendolyn learns from a witness that the kidnapper bore a scarred face, deduces it was Thomas, and heads to the cabin to strike a final, brutal ritual. Thomas overpowers her, kills Gwendolyn, and drags a seemingly dead Gloria outside as the sun begins to rise.
Gloria then revives, and in the voice of Abaddon, turns on Thomas with a ferocity that cannot be denied, vowing to take his soul to hell as the dawn light spills over the cabin and the two souls engage in a final, lethal confrontation.
