Thank you all so much for the wonderful comments on the epilogue. I'm very grateful for all of the support. As promised, here is a notice that the first chapter of the prequel has gone up. (I confess that it's been finished for a few days—since before I posted the epilogue, although I have been editing—and I was trying to make myself wait before posting it to give myself more time to write ahead, but I was just too excited.) The prequel is called Behind Closed Doors: The Prince's Tale and begins with Snape's time at Hogwarts.
I hope to see you there!