Diamond Tiara goes too far and gets caught, now the Cutiemark Crusaders hold her fate in their hooves while Silver Spoon argues for leniency by telling the story of how they met how they received their cutiemarks.
Suri's new collection relies on fabric that only Rarity can produce. When she needs more, does she apologize to her rival, ask politely, negotiate for a fair deal. Not likely, okay?
In an unlikely pairing, Apple Bloom and Derpy Hooves probe Equestria's underpinnings to sort out their cutiemark woes; One defective and the other ambiguous, they struggle to find somepony to remedy the situation.
My name is Sea Swirl and I love swimming in the Ocean. That hardly tells you anything about a pony, though. My name is Sea Swirl and my Mother is a thief and a murderer. Maybe. Maybe that tells you too much.
A long forgotten valley is appropriated as the sanctuary for a new changeling hive. Does this involve the long dead sunstone? Celestia thinks it might and Cadence has her own reason to tag along with the Elements, vengeance!