Everypony knows the story: Princess Celestia's sister had felt neglected and so became the wicked mare of darkness. Case closed, right? She came back, got redeemed, and now they're cool again. Nothing else to worry about, right?

Well, after the events of fixing the time lines, Twilight is a little curious about the specifics of how Luna became Nightmare Moon, and what if Starswirl's spell could have changed that instead. What she receives is a lesson in the nature of those we love.

(This started out as a clop story idea, but became a little too serious for pure sex. It discusses sex though, so be warned. If folks want, I can release a more graphic version. I also don't know if its done. I have thoughts of how to continue it, but not sure how. Also, sorry for any mechanical errors.)