Rainbow Dash enjoys a simple life. But when an old friend she thought she cut ties with in school shows up in Ponyville looking for a second chance, her life suddenly gets complicated. Very complicated.
Rainbow Dash and her human friend decide to help Rarity by watching Opalescence for a few days while the unicorn is away. It seems simple enough at first, but the pair didn't consider one crucial thing. Opal is secretly the devil incarnate.
After experiencing so much stress in such a short amount of time, Twilight and her friends, both old and new, need a break. However, as they take an all expense paid trip to a water park, they soon learn that not everything is as easy as it seems.
It's usually the simplest questions that provoke the most thought. Rainbow Dash is about to learn this fact as she sits down and talks with an old enemy.