A young Victorian-era lawyer, Arthur Kipps, is sent to a remote village on the east coast of England to sort out the affairs of a recently deceased client, Alice Drablow, who lived in Eel Marsh House, an isolated manor in the marshlands. Mourning his wife's death and concerned for his young son's future, Arthur sees this task as an opportunity to secure his job with his firm. Upon arrival in the village, he encounters fearful locals who are openly hostile and urge him to leave. Undeterred and committed to his work, Arthur travels to the eerie, dilapidated mansion.

Once at the mansion, Arthur is plagued by inexplicable events and noises, leading him to discover tragic deaths that have afflicted the village children for years. These incidents seem to be connected to sightings of a mysterious woman dressed in black. During his stay, Arthur uncovers the secret past of the woman, tied to a cycle of revenge and loss. Each step closer to the truth brings Arthur into more peril, as he realizes that the locals’ fear is well-founded. Facing his own grief, Arthur undergoes a deeply personal journey that intertwines with the dark history he seeks to unravel.