A version of the story was published in the magazine Whirlwind in 1890, and Machen revised and extended it for its book publication (together with another story, "The Inmost Light") in 1894. On publication it was widely denounced by the press as degenerate and horrific because of its decadent style and sexual content, although it has since garnered a reputation as a classic of horror. Machen’s story was only one of many at the time to focus on Pan as a useful symbol for the power of nature and paganism. The title was taken from the poem "A Musical Instrument" published in 1862 by Elizabeth Barrett Browning, in which the first line of every stanza ends "... the great god Pan.

    She packs up her sword, her shoes, and her dirty magazines, and prepares to launch her daring escape. But her childhood nemesis won't set her free without a service.Harrowhark Nonagesimus, Reverend Daughter of the Ninth House and bone witch extraordinaire, has been summoned into action. The Emperor has invited the heirs to each of his loyal Houses to a deadly trial of wits and skill. If Harrowhark succeeds she will become an immortal, all-powerful servant of the Resurrection, but no necromancer can ascend without their cavalier. Without Gideon's sword, Harrow will fail, and the Ninth House will die.Of course, some things are better left dead.

       When Mrs. Sorensen’s husband dies, she rekindles a long-dormant love with an unsuitable mate in “Mrs. Sorensen and the Sasquatch.” In “Open the Door and the Light Pours Through,” a young man wrestles with grief and his sexuality in an exchange of letters with his faraway beloved. “Dreadful Young Ladies” demonstrates the strength and power—known and unknown—of the imagination.  In “Notes on the Untimely Death of Ronia Drake,” a witch is haunted by the deadly repercussions of a spell. “The Insect and the Astronomer” upends expectations about good and bad, knowledge and ignorance, love and longing. The World Fantasy Award–winning novella The Unlicensed Magician introduces the secret magical life of an invisible girl once left for dead—with thematic echoes of Barnhill’s Newbery Medal–winning novel, The Girl Who Drank the Moon.