Seventy years after the show, the Elements of Harmony have been stolen. The thieves left no trace, not so much as a single clue to follow. The only lead: a single pony who happened to see them leave. But with the threat of violence if she talks hanging over her head, she's scared and in hiding. Fearing for the safety of Equestria, Celestia and Luna dispatch a small set of ponies, led by royal guard Iron Phalanx, to track her down, find out what she knows, and, above all, keep her safe.

But you don't steal the Elements unless you're up to something big, and the thieves aren't keen on letting that something get out so easily. As they do their best to impede the group's progress, other machinations run, their motives unknown, and the first strike, an attempted invasion of Canterlot Castle, is just the tip of the iceberg. Every lead simply opens more questions as ever more unlikely links are found.

Phalanx and his group aren't deterred by this. Not in the slightest. But the more clues they uncover, the more it's clear the rabbit hole goes far deeper than anyone realizes...