Actually, it’s a prequel to ‘Written By The Winners’ but you get the idea. After trying to wrap her head around how Chrysalis coldly rejected her hoof in friendship even though she did the same thing Twilight did, Starlight discovered what Twilight had done to convince her to give up her power-hungry ways in exchange for friendship.

Needless to say, she is not happy about it. So unhappy, in fact, that she decided to tell another victim of Twilight's friendship-making method and they both want a word with her.