A young girl explores the supernatural while coming of age at a British boarding school.

Set in a remote English school, Hex is the chilling story of one girl's exploration of the supernatural and her own sexual awakening. Shy and socially outcast, Cassie discovers she is cursed by terrifying links to the past. While longing to be popular, but only truly loved by her best friend Thelma (Jemima Rooper), Cassie realizes she possesses dangerous powers. Though terrified by the forces that haunt her, Cassie begins using her new abilities to manipulate people and situations. Stalked by Azazeal, the leader of the Nephelim, Cassie's fate turns dark after Thelma is kidnapped and sacrificed. But Cassie's hopes are restored when Thelma returns as a ghost, determined to protect her from the powers that seek to destroy her.