The only thing that can beat an AI is another AI. Unfortunately for Celestia, she isn't the only one the humans made and the others don't want ponies. Of course, if Celestia has her way that won't be the case for very long.
Lemon Zest is pretty lucky for a pony who just got fried to death. She miraculously comes back as a ghost and stumbles on a haunted school where she can learn the basics of the afterlife. The fee of tuition? Recruiting more ghosts to school.
When an incredible revelation sends Rainbow Dash's life into a tailspin, she finds herself at the mercy of emotions she never thought she had, faced with hard questions and impossible choices.
Rainbow Dash sets out to defeat the legendary witch Twilight Sparkle and collect the five hundred million bit bounty on her head. The one thing she wasn't counting on was Twilight being less evil than she expected.
Pinkamena hates being in control. It's a chore. But now Pinkie is gone from their shared head. Can a sourfaced split personality pass as her better half and solve the mystery of where Pinkie went? No to the first, yes to the second.
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.