Lila, a young queen, faces a shocking turn of events upon her return to the castle, discovering that the king has died. As she gazes into a mirror, she realizes that her reflection is possessed by a separate entity named Lilith. This unsettling encounter prompts her to dash out onto the balcony, causing a stir among the court. The court members engage in discussions concerning Lila's future while retracing her family’s lineage. Soon after, we see Lila preparing to assume the king's responsibilities as she sits on her throne. However, feeling a sense of boredom and self-importance, she quickly abandons her duties and returns to the balcony, where she witnesses an eerie, fiery light.
As the kingdom mourns the loss of their monarch, Lila finds an unexpected sense of satisfaction in the king’s demise. She reveals to the Matriarch and the Aristocrat that she bears a bruise, indicating she was physically assaulted by the king, thus explaining her feelings of contentment. That night, Lilith emerges from the mirror once more, viciously stabbing the sleeping Lila in the abdomen. Awakening from this dreadful nightmare, Lila frantically pulls out seeds from a drawer, urinating on them to check for pregnancy. A troubling sight in the mirror reveals Lilith’s hands caressing her stomach, leaving Lila increasingly disturbed.
Determined to find solace, Lila heads to a bathhouse, but terror forces her to flee as her reflection continues to show Lilith in a menacing light. Seeking to celebrate the king's death, Lila invites her friends for a day of revelry, succumbing to drunkenness and engaging in chaotic behavior in the village. In a state of confusion, she attempts to return to the castle, but after falling from her horse, it runs off. Alone and intoxicated, Lila wanders into a forest, eventually discovering a witch's cabin. The witch cautiously feels Lila’s belly and starts teaching her a Lamaze technique, causing her to panic and flee back to the castle, only to find that the seeds she had previously urinated on have sprouted, signaling her pregnancy.
Frustrated by Lila's immature behavior, the Aristocrat reminds her that she is a common widow without royal blood and thus should be stripped of her title. As a result, Lila faces a sentence of execution once her child is born; a boy will be raised in court, while a girl will face death. Distraught, Lila contemplates drowning herself and her unborn child in a lake. However, feeling the baby kick, she has a change of heart and swims away, seeking refuge in the witch's cabin, as her water breaks. Meanwhile, a maid informs the Aristocrat about Lila's escape.
In a haunting flashback, Lila reveals the dark truth of the king’s demise; she had poisoned his wine after he assaulted her, leading to her pregnancy. Shortly after this, the king collapsed and died. The Aristocrat soon finds Lila after she gives birth with the witch's help. They burn down the cabin, presumably killing the witch, and haul Lila and her child back to the castle. Regaining consciousness in a cell, she discovers that all the guards are dead, an unknown entity having liberated her. Making her way to the nursery, she encounters frightful maids as she retrieves her baby. Carrying her child to the guillotine, she hands the baby to a maid. In her thoughts, Lila envisions a life of love with her child and smiles at the fantasy, only to be abruptly executed.
Meanwhile, Lilith breaks free from the mirror once again, roaming the castle and surveying the corpses of the guards and the Aristocrat, who she likely killed. Picking up Lila's former crown, she contemplates its significance before departing the palace.
