William Browning Spencer has produced a collection of short stories that commingle horror and humor. A number of these tales are cautionary ones. After reading “The Tenth Muse,” you might not wish to interview a reclusive writer who wrote one wildly popular novel and has been silent for decades, even if your father was his closest friend. You might not wish to become a writer at all. “The Indelible Dark” portrays one lost in a dystopian novel he is writing, coming to the slow and unsettling discovery that he carries his own darkness into the mundane world. These monsters aren’t metaphors. Alcoholism might be the monster in “Penguins of the Apocalypse,” but the disease has its own familiar, a creature born in folklore, nothing as warm as that oversized rabbit that Jimmy Stewart talked to in “Harvey.” And it’s got your son. “Stone and the Librarian” isn’t a monster story. It is the story of an unhappy young man who is trying to find his place in a Robert E. Howard world of swords and sorcery but is constantly dragged back to the effete world of his pale and sickly classmates. They read a book by some famous guy, a book called The Catcher in the Rye, in which a kid named Holden keeps going on about how phony everything is. Stone’s book report begins, “If I met Holden Caulfield in an alley, I would kill him with a rock.” In “The Unorthodox Dr. Draper,” a psychologist has abandoned the strict rigor of his professional life for something more improvisational with a client who tells him, “I know when they follow me. I am like a mouse that knows the shadow of the owl because the mouse must be quick or she is dead.”