Trixie has taken over Ponyville and sealed the town in a giant forcefield. Princess Celestia is in Saddle Arabia for important diplomatic talks, so it falls to Princess Luna to deal with the crisis. She immediately sends the Royal Guard to liberate Ponyville, but this task may be harder than it seems.

Many thanks to the Pony Fanfiction Thread in general, and JapaneseTeeth and CDRW in particular, for prereading this.