30 years into the future and the mane six have gotten married and have kids. They each have at least one child in the 18-20 age group. Twilight's 19 year old daughter, Midnight Sparkle, has found the book with Starswirl's secret spell that he never got right. The page where Twilight corrected the spell is missing. Midnight Promised Twilight she wouldn't cast the spell, but she did anyway. You guys can kind of guess what happens next.