For security purposes, Princess Celestia thoroughly makes sure her prison guards are protecting the civilian populace from the often-dangerous ponies held within by checking the prison once a year.

Most of these visits are boring. Some, if any, faults in her guard are minor. The matter is mundane.

But this year, when she hears the whine of a filly, she investigates - and when she finds a small, irresistibly cute changeling filly inside, she instantly falls in love with bright, bubbly, happy Icheal.

Acting on her impulses, Princess Celestia adopts her - but even with the most secure and meticulous of precautions, the relationship is doomed from the start.