Story for you this time by Rainbow Hyphen (Formally Pvt. Flutters)
"Rookie Wonderbolt, Rainbow Dash, awakens one night to find herself in an old abandoned castle with no memory of how she got there. In fact, the latest memory she can recall is her flight with Soarin and Spitfire earlier that day and the wild, spontaneous, storm that appeared from out of no where. From there, her memory is blank. How did she get here? Where exactly is "here"? And where are her fellow Wonderbolts?"
Check it out: Fimfiction.net
(Contains Dark themes)