Let me take this opportunity to rec the hell out of the story that was written for me:
Sherbert Holmes and the Elephant of Surprise, by
miscellanny Yes, it's a Good Omens/Sherlock crossover, and the prompt filled was: "Mrs. Hudson leaves Baker Street. England falls." But of course I wanted the Good Omens cast doing their usual great work at Apocalypse-foiling, and what I got was so, so much better than I could ever have imagined. It's metafictional, it's multilayered, it's rich and hilarious, and it does a much much better job than either canon does with female characters: Madame Tracy, Anathema, and Mrs. Hudson are hilarious, clever, and beautifully drawn. And if you're wondering where Adam Young comes in . . . read it, just read it. You won't be sorry.
I wrote
The Widening Gyre, for
tomato_greens. T-G wanted a story involving the poems "Easter, 1916" or "Leda and the Swan" and said that a historical setting and W.B. Yeats himself as a character would be extra-great, so that's exactly what I did. Historical fiction set shortly before and after the 1916 Easter Rising, a bit of compare-and-contrast between the developing, ever-changing relationship between Aziraphale and Crowley, and the never-consummated but lifelong weird relationship between W.B. Yeats and Maud Gonne. (All the best lines are Yeats's, not mine of course - though the meanest ones definitely come from A. Crowley. No, not that A. Crowley. The other one.)
The Widening Gyre on AO3