Trixie, after returning to Ponyville seeking revenge/forgiveness/redemption/bus fare back to Hoofington, winds up in a coma for three months, through no fault of her own. When she wakes up, she's a little concerned by the hole in the ceiling and the one next to the bed, but not enough to really do much investigating. At least, not until she runs into Rainbow Dash who tells her Twilight has gone missing. Then, things get even weirder when Spike comes crawling out of the basement talking about mysterious books and milk and whatnot. Clearly Trixie has no other option than to get to the bottom of things. She just never expected where that bottom would be.