Lilith by George MacDonald takes the educated narrator, Mr. Vane, on several trips into a parallel world that co-exists with one in time and place, meeting people, observing strange phenomena, and learning from Adam, the first-created human, that God desires all to be saved through death.

Mr. Vane, recently graduated from Oxford, specializing in the natural sciences and given to questions of metaphysics, discovers that his library is haunted by a centuries-old librarian. Vane follows this wispy figure through a mirror for a brief visit to a "region of the seven dimensions." Raven in bird form guides Vane and confounds him with riddles about being and understanding. During a second visit, Raven fails to show Vane how universes coexist in time and space and to get him to lie down among those sleeping in death awaiting resurrection day. Vane rebels, flees, and finds himself back in his own world.

Discovering that his father once enters that other-world, Vane returns, but learns that the father is condemned to do battle with fellow skeletons in a haunted wood. Raven refuses to help Vane, who sets out on an adventure, during which he feels the Moon as a protective force, several times meets animated skeletons and a woman who breaks up their assemblies, a band of "Little Ones" and evil Giants who occupy the same valley, and sets out to figure out how best to help his friends.

While he travels, Vane comes upon the fresh corpse of a woman whom he tries to revive. It is Lilith, the evil Princess of Bulika, enemy of the Little Ones. Raven appears to squawk "I told you so" and Vane tumbles back into his world. There, Raven reveals that he is Adam, the first-created human, and Lilith is his estranged first wife, who has followed them to this world in order to sneak up on Lola. Returning to the other-world, Vane again rebels against sleeping in order to rescue Lona and the Little Ones. In the invasion of Bulika, Lona dies at her mother's hand, and Lilith is taken to an inquisition to reunite her with God. A long battle over free will and determinism ensues before all sleep in Adam's house. Vane comes to understand the beauty of all creation and is about to face the Ancient of Days with Lona when they are parted and he returns to his house to await his restoration when he dies.