In a medieval world filled with magic and dark forces, Master Gregory, an aging Spook and warrior specializing in fighting malevolent supernatural entities, seeks an apprentice to carry on his legacy. His latest recruit is Tom Ward, the seventh son of a seventh son, endowed with unique abilities powerful enough to confront the evil they face. Tom's training begins under urgent circumstances as the malevolent witch, Mother Malkin, escapes from her confinement, threatening to unleash chaos and destruction upon the world. The two must navigate through treacherous landscapes, encountering various creatures and dark magic, all while Gregory imparts his wisdom to prepare Tom for what lies ahead.

As their journey progresses, Tom learns to harness his innate powers and confronts his fears, drawing closer to his ultimate test against Mother Malkin. Along the way, Tom meets Alice, a mysterious girl whose loyalties are uncertain, adding complexity to his quest. Together, they face battles that test their strength, courage, and loyalty. The stakes grow ever higher as they advance towards the inevitable confrontation with Mother Malkin, where the fate of their world hangs in the balance.