The Happy Prince

"The Happy Prince" was a short story written by the Irish author Oscar Wilde at some point after his visit to Deadwood in March 1882. Clara Oswald had read the story and was familiar with its plot. When Wilde commented on the sadness of Calamity Jane believing her true love Wild Bill Hickok had returned, only to find his heart replaced with stone, Clara noted the similarly to "The Happy Prince". Upon realising he had not yet written the story, she quickly told him to forget what she said. (COMIC: Dead Man's Hand)

Because it involved a "living statue" (PROSE: The Secret Lives of Monsters) whose heart was replaced with stone, (COMIC: Dead Man's Hand) "The Happy Prince" was among the works of literature speculated to be spawned by an innate knowledge of the existence of Weeping Angels. (PROSE: The Secret Lives of Monsters)

Behind the scenes
"The Happy Prince" was published along with four other children's fairy tales in Oscar Wilde's 1888 book.