This was a story I had seen a few years back. It was about Spike wondering why he was a wingless dragon (this was prior to season 8), and he and Twilight discover a journal by scientist which tells about another wingless dragon. The pair, along with Rainbow, Rarity, Applejack, and Pinkie Pie (Fluttershy staying behind) then go on a journey where they eventually find an underground kingdom inhabited by peaceful dragons. It was a pretty epic story, but unfortunately, I neglected to favorite it, and I can't remember the title. Can anyone tell me what it was, provided it's still on the site?