Canterlot is renowned for its class and sophistication, although after the Changeling attack, the capital city of Equestria seems to be much more on edge than usual. At the centre of this is the Canterlot Royal Guard, the group that polices most of the lands.

Worries of a Changeling presence are high, and nopony knows who they can trust. But when contact from Ponyville halts, everypony fears the worst, and, concerned for the safety of her student and her friends, Princess Celestia sends a group of Guards to investigate.