In 1950s London, renowned British dressmaker Reynolds Woodcock comes across Alma, a young, strong-willed woman, who soon becomes ever present in his life as his muse and lover.

A young couples lives are turned upside down when the birth of their first child is accompanied by terrifying entities that threaten their newly formed family.

During a handover to the head of counter-terrorism of MI5, Harry Pearce, a terrorist escapes custody. When Harry disappears soon after, his protégé is tasked with finding out what happened…