Shown in a nonlinear narrative, this film intricately weaves together the interconnected stories of three generations of the Mallari family: Juan Severino, Johnrey, and Jonathan, each set in different time periods.
The tale begins with Juan Severino, who arrives in Magalang alongside his mother, Doña Facunda, to assume his role as the local priest. While he is away pursuing his religious duties, Facunda falls victim to dark magic orchestrated by church servants, particularly Maria Capac, who lures her into a secretive occult ritual, transforming her into a manananggal. Upon discovering this horrific transformation, Severino confronts Maria, who heartbreakingly informs him that his mother is afflicted with a terminal illness that can only be remedied by consuming human flesh. Consumed by despair but driven by a twisted sense of love, he is torn between preserving his mother's life or damning his soul. Eventually, he succumbs to his darker impulses driven by a sinister alter ego, leading him to commit chilling acts of murder against a corrupt landlord and two women. Facunda, oblivious to her metamorphosis and her son's gruesome actions, inexplicably recovers after being fed her son's victims' entrails. As these murders escalate, the panicked residents of Magalang abandon their homes.
In a twist of fate, a man resembling Severino, who claims to be his future descendant, confronts him. The man warns Severino that his legacy will be marred by the label of a killer. He urges Severino to acknowledge his heinous acts and his mother's transformation into a manananggal. Their confrontation is abruptly interrupted when the Guardia Civil arrives and takes Severino into custody. In the ensuing chaos, Maria makes her escape with Facunda.
The narrative then shifts to the era of the Hukbalahap Rebellion, where Johnrey arrives in Magalang to document the events of the time, taking residence in his ancestral home. During his stay, Johnrey encounters the aftermath of an aswang attack, though his boss dismisses these occurrences as mere CIA operations. Unperturbed by skeptics, Johnrey plunges into the mystery of the murders plaguing the town, sensing a connection to his ancestry.
In a surreal twist, Johnrey experiences vivid dreams transporting him back to 1812, where he meets Severino, Doña Facunda, and the ghosts of Severino's victims, alongside a boy named Jonathan, who claims to be his grandnephew from the future. This otherworldly experience reveals their shared ability for astral projection and time travel. Johnrey, now armed with Jonathan's blanket, returns to the past to document the harrowing lives of Severino and Facunda, creating two film reels addressed to Jonathan.
Upon returning to his time, Johnrey is confronted by an elderly Maria Capac and a threatening figure named Conching, revealed to be Maria’s granddaughter, who holds his wife Felicity hostage, along with the aged Doña Facunda. Facunda, refusing to revert to her previous cannibalistic ways since Severino's arrest, faces a life-threatening ultimatum. In a desperate bid, Johnrey swallows a black chick residing within Facunda, leading to her disintegration into ashes. In the throes of transformation into a werewolf, Johnrey slaughters Conching and Maria. Afterward, he instructs Felicity to bury him alive to end the curse.
As time progresses, Jonathan is haunted by premonitions concerning his fiancée, Agnes, compelling him to return to Magalang to avert a tragedy. Accompanied by Lucas, the son of a family servant, and Lucas' niece Amal, he uncovers disturbing truths about his ancestors. Meanwhile, a series of murky murders by an individual dressed as a priest raises alarm and suspicion about Jonathan's possible connection to it. In a heart-wrenching moment, Agnes discovers Lucas’ ties to the occult-worshipping Alarcon family, which includes a lineage tied back to Maria Capac. A shocking revelation unveils Lucas as the perpetrator, after he is seen objectifying himself in a terrifying display of self-flagellation before a statue of Severino.
In a frantic sequence, Agnes flees to the safety of the Mallari residence but not before a confrontation leads to her being brutally stabbed by Lucas. The agony escalates as Jonathan returns to 1812, engaging in a desperate struggle with Severino, who denies involvement in future events. Upon awakening, he encounters Lucas, who endeavors to convert Jonathan into a vigilante steeped in Alarcon customs. After a fierce clash resulting in Lucas's death, Jonathan faces the tragic sight of a dying Agnes as Felicity's film casts an eerie light on the remnants of John's legacy. In the climax, Jonathan resorts to exhuming Johnrey’s grave, disobeying warnings from spirits against reviving the curse, and decapitates Johnrey to transfer the chick to Agnes.
In the aftermath, Jonathan, Agnes, and Amal settle into the Mallari residence. As eerie as it is poignant, Agnes confronts Jonathan for metamorphosing her into a monster, foretelling her hunger under the full moon. Jonathan's unsettling gaze directed at the camera leaves the audience pondering the cycle of horror that may never truly end.
