Little Rainbow Dash is loyal to one pony and one pony only: herself. It's a simple system, and it gets her through the days. But that all changes one stormy summer afternoon at flight camp, when another pegasus blunders into her life--a pegasus with whom she shares nothing in common.

Rainbow Dash bets that Fluttershy couldn't pull off a prank in time for April Foal's Day. Fluttershy says that she can...maybe.

When Twilight finds herself suddenly losing control over her magic, our six equine heroes find themselves drwn back to the site where they became the Elements of Harmony to confront an ancient creature, older than Equestria itself.