“Once on a Time”

John Keats is very specific about when “Lamia” takes place. It’s “before the fairy” had come to the land. It’s “before King Oberon.” In fairy stories, and especially in Shakespeare’s A Midsummer Night’s Dream (ca. 1595), King Oberon and Queen Titania rule a court of fairies, and Keats imagines that the fairies, when they came, “frighted away the Dryads and the Fauns” and “drove Nymph and Satyr from the prosperous woods.”

Dryads and fauns, nymphs and satyrs: these are magical creatures from...