On a request from Princess Celestia, Twilight Sparkle and the rest of the mane six explore an abandoned mansion located deep in the woods. While doing so, they unwittingly stumble across an enchanted mirror that scrambles their DNA and pops out three brand new bouncing baby ponies. Hilarity and drama ensue as the mane six must cope with being suddenly thrust into motherhood, as well as protect their new foals from a dark god that wishes to use them for his own sinister gain.
- Big Bad: Sleipnir, though he is currently Sealed Evil in a Can and giving his followers orders from afar.
- Body Surf: Sleipnir's most dangerous ability, as it makes him really hard to stop for any real length of time.
- Has Two Mommies: The foals of the Mane Six, via an accident with a magical mirror.
- Homosexual Reproduction: The mirrors can mix DNA from any two (or maybe more) sources, regardless of the species or gender of the donors.
- I Have Many Names: The Big Bad has a variety of titles that people use, though he doesn't seem to use them much.
- I'm Melting!: The fate of a "Snow Mare" in a bonus 20 Minutes into the Future chapter, when the Mirror-Born foals blast her with the Elements of Harmony. Bonus points for wailing the Trope Namer quote as she's done in.
- More Bonus points for the Elements turning the Snow Mare into steam rather than liquid water, and not leaving any trace of her behind; not even a puddle.
- Magic A Is Magic A: In addition to any canon examples, the Body Surf technique of the Big Bad only works if the being his soul is trying to hop into and and reshape is sentient and directly created via a mirror. Any descendants of said mirror created beings are fully immune.
- Rewrite: The author is in the process of rewriting the story.
- Sealed Evil in a Can: Sleipnir's minions are sealed away in the form of Equestria's stars via a spell of Luna's (at least his original followers, he's gained more), with the spirit of the Big Bad himself sealed away in the largest star, Polaris.