In an alternate world where everything and everyone is made of Lego, the Equestria Girls make another attempt to simply enjoy themselves without worrying about fighting any evil or otherworldly magic by attending the Starswirled Music Festival.

While everyone has their own plans to have a good time at this music festival, Sunset's involve spending the first day with Pinkie Pie for their one and only opportunity to watch a live performance of their favorite band, PostCrush. But things get weird when Sunset finds herself repeating that first day over and over again.

Caught in a time loop with seemingly no one else to share her experiences, Sunset Shimmer must try to figure out what caused it and how to stop it, and hopefully not go completely crazy in the process.