We're thrown for a bit of a loop by learning that Dawn actually had another run-in with Twilight long ago, stalking and attacking her while she went home from her lessons (turns out Twilight didn't live in Celestia's library full-time, at least at first), and ending up in a scuffle with Shining Armor before the city guard dragged them both off. And here I'd thought a zero-tolerance policy on lifting a hoof in defense was limited to Exit Through Canterlot.
In the present, Dawn partakes in another classic villain cliche: getting chewed out by her shadowy benefactors impatient for results. She reminds Jugurtha, her Grevyian contact, of all the powerful foes Twilight and her friends had defeated and that she will need to break the group apart before striking at Twilight, instead of the other way around. A threat against Laurel cools her down enough to add that Shining Armor will be out of the picture soon, though. Jugurtha stalks off and Dawn continues reading up on Mind Control for Dummies, while remembering another favorite literary passage from a story about Celestia ("The Once and Future Princess") and apparently casting herself in the role:
"Yet will I be content, so long as one pony yet smiles. So long as eager light remains in Luna's eyes. I'll bear the hatred of all pony-kind so long as there are little ponies left to hate me. For their freedom will be my salvation, Luna's laughter shall be my grace, their innocence shall be the forgiveness of my sins for all I do I do for them. I will be princess, I will wear the crown and sit upon the throne, yet I will their devoted servant be while the sun yet shines....
"I will do right by them, when I have raised our Canterlot. By all of them, who are the most deserving ponies in Equestria. My rising shall be the means and instrument of their ascent to greatness. I'll be princess, but still I'll serve them all my days. My friends. It is for their lives, for their happiness, I do these things."
The business of the city continues apace, as while Shining Armor and Lancer finally track down the old stallion who sold Dawn the poison (and get a physical description of his customer that Shining finds frustratingly familiar), Celestia attempts to negotiate with the zebra ambassadors with the help of Rarity, Rainbow and Pinkie. A more logical world wouldn't let the latter two anywhere near diplomacy, but fortunately the Quaggain dignitary Sophoniba is pretty good-humored with regard to whoopee cushions. Things don't get much further, though, and Celestia gets the impression that Lord Mathos is less interested in dealmaking than in stalling. Rarity eventually retires, only to discover another note from "Shining" and freaking out over the "prank". Fluttershy overhears but Rarity passes it off as bring upset at Opal (who is apparently male here) for making a mess, and Fluttershy notes that talking things over would work much better, sadly something that nopony else seems to agree with at that moment.
Twilight continues banging her head against the quest for an antidote, hampered by the Tears of Nightmare Moon apparently somehow consisting of the usual ingredients for amnesia antidotes, somehow perverted, possibly magically. Spike suggests that dark magic might be involved, and despite his own immediate misgivings, Twilight latches onto the idea of using as much dark magic as possible to study it and untangle the problem.
Coming full circle, Shining finally remembers his long-ago encounter with Dawn and recognizes her as the poisoner- but before he can warn his sister, Dawn herself arrives, and she's still quicker on the draw with a spell....
