The story of The Midnight Folk is the quest for buried treasure that needs to be regained in order to restore family honor. Although personal qualities are needed on Kay’s part, the immediate impression is that the past is acutely alive, seeking to redress evil and injustice. The past also lives generationally, and thus it can work for evil as well as good. Abner Brown seeks to perpetuate the evil of his father and grandfather through occult means, whereas Twiney Pricker, now Sir Piney Trigger, has repented his past and is thus helping Kay. Roper Bilges continues the evil of his past but only in a small way, as a poacher.
It is never quite clear what benevolent forces arrange the perfect timing of many of the revelations. Beside the force of a living past there is the help of the Midnight Folk and the goodwill of the two servants, Susan and Ellen, who supply vital bits of historical information at the right time. There is also much goodwill to Kay from neighbors who remember the Harker family. Thus, “all things work together for good,” even if Kay cannot always see it at the time.
Nevertheless, there is a deep sense in the book that evil forces are seeking to rob Kay of his inheritance once and for all. The inheritance is not the treasure as such, since that belongs to the cathedral. It is not even the family’s good name or fortune. It is ultimately the imaginative richness of a child’s inner world. The witch/governess takes Kay’s toys (and imaginative friends) from him and seeks to prevent him from playing games or doing things he wants, confining him to a narrow curriculum of abstruse school lessons. Kay is shown little love by anyone in the household and as a consequence is full of fears and lonely. As the story proceeds, Kay not only learns courage but also finds love and friendship and is able to stand up to the evil forces around him. His imagination blossoms as he enters into a fantastic secondary world, where his fears and loneliness disappear.