(Takes place within the universe of A Captain's Reflection, and just before the time skip in "The Last Problem".)
Rainbow Dash is still trying to get her bearings as the new captain of the Wonderbolts, learning all the ins and outs of what it means to lead the team. Even though she has some of the other senior bolts to lean on for support, being captain is very much a learning experience for Rainbow.
Things only get more complicated when an unexpected rival shows up in the form of Lightning Dust. She's resurrected and restructured the Washouts, and wants to challenge the Wonderbolts to see who truly deserves to be known as Equestria's greatest flyers.
Facing a dilemma about how best to put Lightning Dust in her place, Rainbow Dash decides to swallow some of her pride and reach out to the old captain: Spitfire. In particular, Rainbow hopes the former captain will come out of retirement for one last grand performance.