In a hole in the ground there lived a man writing “The Hobbit.”

O. K., it wasn’t a hole in the ground; it was 20 Northmoor Road in Oxford, England, where, in the drawing room of a spacious, comfortable home, Prof. J.R.R. Tolkien wrote “The Hobbit,” and later “Lord of the Rings.”

Meanwhile, in a room in an apartment in Chicago, there lived a man writing “The Story of the Vivian Girls, in What Is Known as the Realms of the Unreal, of the Glandeco-Angelinian War Storm, Caused by the Child Slave Rebellion.”

This was Henry Darger: American author, outsider artist and visionary. His 15,145-page, single-space manuscript describes an epic world of fantastical beasts and charmed children, fighting against a system in which the young are enslaved. His book and its accompanying illustrations were unknown until after his death, when they were discovered in his apartment, 851 West Webster Avenue, in Lincoln Park.

I thought about these two overlapping lives last week — Tolkien the professor, Darger the hospital janitor. Two Catholics, orphaned young, both born in 1892, both dying in 1973. I was taking in the exhibition of Tolkien’s manuscripts and maps and artwork at the Morgan Library and Museum in New York. There I stared at the relics of Middle-earth: original manuscripts, watercolors, a roughed-out map of Gondor in the author’s own hand.