In 1944 post-Civil War Spain, young, imaginative Ofelia travels with her pregnant, ailing mother, Carmen, to a remote
military outpost. There, they must live with Carmen’s new husband, the ruthless and sadistic Captain Vidal. Vidal is obsessed with crushing local Republican rebels and ensuring his unborn son is born safely to carry on his legacy. Desperate to escape the harsh, brutal reality of her new life, Ofelia finds solace in fairy tales.One night, a giant insect leads Ofelia to a crumbling, moss-covered labyrinth near the homestead. Inside, she meets a mysterious faun who reveals a stunning truth: Ofelia is actually Princess Moanna of the Underworld, and her true parents are the King and Queen. However, to reclaim her immortal status and return to her magical kingdom, the faun insists Ofelia must successfully complete three perilous tasks before the full moon.Concurrently, the dark reality of the war presses in. Mercedes, the house maid, and the local doctor secretly aid the starving maquis rebels hiding in the nearby mountains. Driven by her duty to the
magical realm, Ofelia undertakes the faun's terrifying trials. In the first task, she retrieves a magical key from the belly of a giant, grotesque toad. For the second task, she must retrieve a dagger from the lair of the Pale Man, a horrifying, child-eating monster. Despite the faun’s strict warning not to consume anything in the monster's feast, Ofelia eats two grapes, awakening the creature and narrowly escaping with her life. Enraged by her disobedience, the faun refuses to give her the third task.Tragedy strikes when Carmen dies in childbirth, plunging Ofelia into deep despair. Meanwhile, Vidal discovers that Mercedes and the doctor are spies. The doctor is executed, but Mercedes bravely stabs Vidal and flees to the rebels. When Vidal captures Ofelia later, the faun reappears, offering a final chance at redemption: she must bring her newborn baby brother to the labyrinth and shed a single drop of his innocent blood.Ofelia steals the baby and flees to the labyrinth, but Vidal pursues her. Refusing to harm her brother, Ofelia stands her ground, and Vidal shoots her. Mercedes and the rebels arrive moments later, executing Vidal for his war crimes. As Ofelia bleeds out in the labyrinth, her consciousness transcends her broken physical body. She finds herself in a golden throne room, welcomed by her royal parents and the faun. Though her mortal body has died, her pure-hearted sacrifice allows Princess Moanna to return home at last, leaving Vidal’s bloody legacy behind forever.