This story is a sequel to My Little Alicorn

After the events of "My Little Alicorn," everything seemed to be back to normal...except for one pony. Prince Blueblood is now trapped as a colt, his title, possessions and birthright stripped for his crimes. Before Princess Celestia will return him to normal, however, he must prove himself by attending Magic Kindergarten. Even worse, his current situation has attracted the vengeful gaze of two ponies he has offended in the past: the Captain of the Royal Guard and the Moon Princess.

Will Blueblood rise above his past self and emerge a better pony? Or will he sink back into his old depravity, and be stuck a colt for the long term?

Note: This is a sequel to "My Little Alicorn," so you might want to check that out first.

The Cutie Mark Crusaders ask Rainbow Dash and Fluttershy about what happened just after the events of the Cutie Mark Chronicles; specifically, what happened to Fluttershy and Rainbow Dash immediately after the race. Reluctantly, Dash and Fluttershy delve into a tale. A tale of a young Fluttershy's amazement at the world she had landed upon, and a filly Dash's desperate quest to save her from that most evil of places: THE GROUND.

Luna has had enough of Celestia's games, and has found the perfect means of revenge. Using a long-forbidden spell, she transforms her sister into little more than a small filly, all so she could pull the greatest prank ever. Unfortunately, she soon learns that before you fool around with dangerous magic, you really need to read the fine print...

A sequel can be found here.