Rarity accidentally sees Rainbow preparing to a trip in Canterlot under a completely different Persona. Rarity wants to tag along at a future date. She finds that Rainbow really sticks to her other persona. Maybe a little too much...
It's recommended to read the prequel but it's not necessary. Stuff makes more sense.
Read in either of these orders you like. But as of now they barely connect.
Chronological order:
Fluttershy's Second Greatest Secret
The Club's Connected to the Boutique
Well, That's Just Silly
Chronologically made:
The Club's Connected to the Boutique
Fluttershy's Second Greatest Secret
Well, That's Just Silly