Princess Cadance noticed how lonely Princess Celestia seemed on Hearts and Hooves Day.
She decided to send a small love spell her way, as motivation to help her find a special somepony, even if it's just for a day.
Cadance immediately regretted it upon finding out who it was.
Special thanks to Mickeymonster for allowing me to use the cover image!
Edit: Mickeymonster has made a colored version of the cover image! Original image: http://fav.me/d4mozkh