On a warm and very sunny day in Equestria, Rainbow Dash finds her Cutie Mark glowing, and races to the castle. Finding that the Map has called upon her to solve a friendship problem, she rushes off towards Cloudsdale to meet Thunder Dust, the little brother of Lightning Dust, who wants to go back to his old home on the outskirts of Manehattan, but is fearful of his sister being there waiting for him. Convinced and encouraged by Rainbow Dash to go anyways, she and Thunder zip off towards the city, where secrets don't keep, and a neverending pain lingers.