Grace Burnham, Amber Heard, a seasoned alienist from New York, travels to a remote Colombian plantation to tend to Martin Marquez, a boy rumored to harbor extraordinary abilities. On the sprawling Nicolas Marquez ranch, Nicolas, [Eduardo Noriega], initially urges her to leave, yet Burnham remains steadfast, convinced she can help the boy despite the village’s skepticism. A fraught dynamic unfolds as Father Antonio, [Luca Calvani], the local priest, explains that the town’s only train arrives once a week, a detail that underscores how cut off they are from the outside world.
Martin is kept locked away, and when Burnham finally meets him, the boy reveals a troubling confession: he killed his mother, Isabella. Isabella, Sophie Amber, was teaching him to ride when tragedy struck and the horse trampled her. The tale deepens as Father Antonio notes that, at Martin’s birth, locusts descended and devastated the crops, foreshadowing the fear and superstition that grip the village. Burnham, Antonio, and Martin later visit the burial site of Martin’s mother to pray, a moment that intensifies the mystery surrounding the boy’s powers.
The arrival of Father Gavira, [Yari Gugliucci], intensifies the tension. Gavira despises Martin and has sown suspicion among the villagers, who come to believe that Martin is the Antichrist. In a frightening turn, Martin causes a horse to panic, and the rider’s shot wounds Gavira’s arm. Gavira orders Martin’s capture, while Father Antonio keeps the others at bay long enough for Burnham to spirit Martin back to the ranch. Back home, Burnham and Nicolas tend to a gravely injured Antonio, who reveals that Gavira had pressed for an exorcism that Nicolas refused—something that has left the village blaming Martin for every misfortune.
Nicolas explains another layer of tragedy: while Isabella was pregnant with their second child, the baby was stillborn because it could not be baptized; Gavira said the child could not be buried in the cemetery, so Nicolas buried it near the lake. To comfort his wife, Martin, seeking to ease his mother’s sorrow, dug up the child and offered it to her—an act Burnham interprets as a sign of Martin’s complexity rather than malice.
Believing Martin’s condition might be savant-like, Burnham returns to the village to explain her assessment to Father Gavira, hoping to defuse fear with science. The crowd responds with hostility, and Burnham is nearly flogged before Nicolas intervenes. The conflict erupts later when villagers attack Nicolas’s stable; Martin, drawn to protect, enters the burning structure, and Nicolas carries the corpses of the dead villagers to Gavira’s church as a stark message.
Across the next days, Burnham earns a new sense of purpose when Father Antonio praises her as an instrument of God’s mercy, suggesting that faith and doubt can coexist in the same heart. Burnham’s conversations with Martin become more intimate: she asks what he fears, and he asks what she fears—their exchange reveals her own doubt about her vocation, even as she remains determined to help him. The village’s fever pitch continues to rise: a maid dies from the same illness, and Burnham’s confidence wavers, though Nicolas reassures her of the good she has done for his son.
With the mob growing more dangerous, Nicolas concludes that Martin and Burnham must leave the village, a plan Father Gavira tries to thwart by rallying the townspeople to attack the ranch. Father Antonio pleads for calm, but Gavira silences him with lethal force. Burnham and Martin attempt an escape, yet they are captured by angry villagers. Gavira closes in for a final strike, but Nicolas—the ranch’s steadying force—arrives mortally wounded and gives Martin a last chance to survive. Martin’s abilities erupt once more as the flames rage, and Gavira’s pistol backfires, ending the zealot’s threat. With Nicolas dying, Burnham seizes Martin and they make their way toward the railway station, the boy’s fate hanging on the last train out of a village where fear nearly swallowed them all.
