Twilight now has full reigns over ruling Equestria. Celestia is left with very little to do and the boredom is starting to get to her. Just as she starts to wonder what she will be doing for the rest of an eternity Discord shows up. He has an idea, she should rule for just one more day and in addition, they should switch places. That's right Discord rules as Celestia and Celestia is now Discord, whoever breaks character first looses and has to serve the others every whim.