A routine rescue from a no-name villain goes wildly awry as Celestia is flung into the lethal, living nightmare that is Tartarus. No great problem for an immortal, but to Celestia's absolute horror, Twilight has followed her in.
Rainbow Dash sets out to defeat the legendary witch Twilight Sparkle and collect the five hundred million bit bounty on her head. The one thing she wasn't counting on was Twilight being less evil than she expected.