While house-sitting the castle at the Crystal Empire whilst the royal family is on vacation, Twilight stumbles across a rather unexpected tool that Cadence uses to make her job as the 'Princess of Love' a bit easier to manage. What looks to be a simple filing cabinet full of records on who-loves-who in Equestria, however, turns out to be a magical artifact of tremendous cosmic power. As a result, Twilight's attempts to optimize Cadence's file organization leads to some rather wacky shifts in everypony's relationship status.