Mark Easterbrook finds a priest dying in an alley and is accused of the murder by the police. With the help of art restorer Kate Mark, he sets out to prove his innocence using a list of names handed to the dying priest. Everyone on the list, except for one person, has died recently, seemingly from natural causes. Mark and Kate discover a connection to the mysterious house 'The Pale Horse', and its three eccentric women who claim to be witches.