As fate would have it, Billy Bradley, an apprentice to the enigmatic Gregory, unexpectedly encounters his mentor in a lively tavern. The atmosphere is charged with anticipation as the bells toll, signaling Gregory for an urgent matter. Yet, Gregory, casually sipping his drink, remains stubbornly unyielding, leading Billy to make another attempt to persuade him. Unfazed by Gregory's resistance, another patron interjects, only to receive a deftly delivered blow from Gregory's swift hands. With the commotion settling, Billy guides Gregory to the home of a young girl enveloped in an unsettling presence. Upon arrival, Gregory confronts the child, tuning into her whispering voices filled with dark intent. This unsettling revelation sends him racing for answers: Malkin has returned, thirsting for revenge against Gregory.
Without hesitation, Gregory and Billy embark on a mission to find the elusive Malkin, their resolve palpable. Their quest culminates in a face-off with the witch, who emerges from the shadows with sinister taunts. Transformed into a monstrous entity, she lunges at Billy, who bravely tries to restrain her but soon finds himself ensnared in a cage alongside her. Malkin seizes this moment, her claws piercing Billy's neck as she injects him with a lethal poison, ultimately claiming his life.
As word of this tragedy spreads, Tom Ward and his sister Cate, along with their mother Mam, lead their daily lives in a nearby village. Tom is tormented by strange visions of spirits and creatures, yet their meaning eludes him. This changes when Gregory arrives, recognizing Tom's innate connection to the mystical world. Identifying him as the seventh son of a seventh son, Gregory seizes the chance to take him on as his next apprentice. Mam bestows her blessing upon Tom, giving him a sacred stone before he embarks on his training under Gregory's guidance.
Meanwhile, Malkin returns to her lair, only to discover her sister, Bony Lizzie, lying charred and lifeless. Fueled by a desire for vengeance against Gregory, Malkin embarks on a mission to restore Lizzie's beauty.
The villagers soon become restless, turning their accusing fingers toward an innocent young woman named Alice. However, Tom stands up for her, unaware that Alice is connected to the unfolding drama as Lizzie’s daughter and Malkin's niece. As Tom adjusts to his new life with Gregory, he encounters Tusk, a troll-like creature, during a night expedition. In a suspenseful moment, he faces off against a colossal armored creature but is saved by Gregory’s prowess. Later, Gregory tests Tom’s resolve in a duel, questioning whether he can handle the challenges posed by dark forces. Angered, Tom throws his sword in Gregory’s direction, an act that unexpectedly earns Gregory's respect. In the aftermath, Gregory imparts cryptic knowledge about Malkin and her minions, hinting at their evil plans.
When Tom crosses paths with Alice again, he learns she is a witch, although she insists that not all of her kind are malevolent. She reveals her lineage—her mother being a witch and her father a gypsy. As Tom wrestles with these insights, Gregory is summoned to the city, taking Tom along to confront a fearsome beast that has terrorized local men. Initially appearing as a bear, the creature is soon revealed to be a shape-shifting minion of Malkin. After Gregory triumphantly transforms the beast back into its human form, he implores Tom to deliver the final blow – a daunting request that Tom struggles with. Despite his hesitation, the villain meets a fiery end, deepening Tom's sense of unease.
Alice later reveals a significant truth about Gregory's past: he once loved a witch deeply. This revelation sparks Tom's curiosity, leading to a brief but charged moment between them. However, soon after, Tom is gripped by a prophetic vision depicting Malkin attacking Gregory and a city engulfed in flames — a foreboding omen that weighs heavily on him.
Upon returning to Gregory, Tom learns of the brutal murder of Gregory's beloved witch, an event that sparked his vendetta against all witches. As their journey unfolds, they encounter a lumbering beast in the woods. Gregory urges a quick escape, and together they narrowly avoid disaster by leaping into a river below. They find refuge on a makeshift raft but are soon confronted again by the monster, which captures Tom. In a moment of bravery, Tom plunges a blade into the creature's skull just before they tumble over a waterfall to safety.
After reuniting with Gregory, Tom learns about his mother's mystical abilities and discovers the importance of the sacred stone he possesses. In a twist of fate, Lizzie uncovers Tom's lifeless form, momentarily stunned by the stone's significance before disappearing. As Tom and Gregory share experiences of their recent battles, Lizzie returns to Malkin with tales of the sacred stone and its connection to her lineage. The witches, fueled by vengeance, transform into fierce beasts and launch an attack on the town.
Amid the chaos, Mam protects her daughter while unleashing her own powers against the intruders. Enraged, Malkin accuses Mam of treachery and strikes her down mercilessly. In this turmoil, Alice encounters Tom one last time, snatching the stone from him before her departure.
With the witches' fury rising, Radu leads a horde of minions against Tom and Gregory. They fight bravely but are ultimately overpowered, leaving Tom for dead as Gregory is captured. In the depths of his despair, Tom is visited by a spectral vision of his mother, who reveals the truths about her own demise at Malkin's hands. This encounter ignites a spark within Tom, pushing him toward his destined confrontation with the darkness.
As the witches conspire, Malkin attempts to seduce Gregory, but Alice seizes this moment to reclaim the stone, breaking Malkin's influence over him. As the minions launch a final assault, Tom awakens from his near-death state, channeling his inner fury to incinerate the invaders.
In the ensuing battle, Radu transforms into a fearsome dragon, challenging Gregory to a duel on the ground. Guided once again by his mother's spirit, Tom steps into the fray. The climactic struggle unfolds, with Malkin and Lizzie morphing into terrifying beasts, each determined to thwart Alice's mission. As her life slips away, Malkin's fate intertwines with Gregory's during their final confrontation. Amid the chaos, Tom bursts in with a precise strike, plunging his blade into Malkin's heart, finally silencing her terror.
With the malevolence extinguished, Tom shares a heartfelt moment with Alice before she departs, feeling the weight of destiny upon him. He prepares to follow Gregory on his continuing journey, but is met with a poignant revelation: Gregory intends to stay behind as the guardian of Tusk, the new Spook, committed to protecting the town from residual dark forces. With a heavy heart, Gregory steps into the unknown, leaving Tom to face his own destiny as the mournful bells toll in the distance, beckoning him toward an uncertain future.
