Trixie's cruise trip was ruined the moment she met up with Pinkie and Sonata. After they got stranded on a desert island due to a hurricane, Pinkie and Sonata were trying to have fun while Trixie was determined to get herself off of the island.
Sunset Shimmer finally returns home to Equestria to right her old wrongs, unfortunately the sins of the Human World follow her back and put everypony in Equestria in danger.
A year after the battle of the bands, graduation nears, a familiar face returns, a pure heart is corrupted, enemies become allies and the fate of all reality hangs in the balance.