This story is a sequel to Prepared for her Return
On a boring night Princess Luna decides to delve even deeper into her sister's book "Sunset's possible returns". What other crazy scenarios did Celestia come up with?
If you haven't, read the prequel first. Otherwise this one won't make much sense.
"Teen" and "Crossover" tags just to be safe.
Edit:2/23/17 This time I'm sure it got featured