http://derpyhoovesnews.com/entertainment-weekly-preview-keep-calm-and-flutter-on/
Many thanks to http://family-room.ew.com/2013/01/18/my-little-pony-friendship-is-magic-discord/.

My Little Pony: Friendship is Magic -- Keep Calm and Flutter On
(January 19, 2012)

"Princess Celestia tasks the ponies with reforming Discord, a mischievous spirit of disharmony, but Fluttershy is the only one who is willing to give him a chance." —Zap2it