Humanity's space exploration ultimately took the form of billions of identical probes, capable of building anything (including astronauts themselves) upon arrival at their destinations. One lands in Equestria. Things go downhill from there.
Transported away from their home far across the galaxy to a planet called Earth, Sunset Shimmer and Twilight Sparkle must devise a way to cope, learn, and find their way back home to Equestria, by joining Starfleet.
Rainbow Dash finds a maimed, unconscious young colt on the edge of Ponyville and rushes him to the hospital, but nopony knows who he is and something about him seems off...
Celestia lands on Earth as a common Arabian mare. Without magic, speech, not knowing the language, she seeks her way home. First though, she needs to make some friends and restore her freedom.
As a fan of the show, I always loved Rainbow Dash and her cutie mark, but I never wanted it to appear on my leg! Now that it has, all sorts of things are getting weird around here. I'm a guy, not a mare! Cartoon ponies aren't real... right?
Equestria finds itself under attack and grossly unprepared for a new and ruthless threat. Fortunately, a certain wizard was pulled into the fight as well, and must lend his knowledge to Equestria and its protectors to help combat this threat.