The ancient kingdom of Zaldia, the Platinum Kingdom, has stood apart from Equestria for centuries, its culture and its ponies fiercely independent and cultivating a culture of propriety, etiquette - and secrets. Trixie and Lyra, Elements of Magic and Loyalty respectively, find themselves in this land for reasons that appear simple enough on the surface. They soon find themselves embroiled a game of conspiracy and treachery - one that threatens not just their lives, but the whole of Equestria...

Short version: Tom Clancy Writes Pony. A Lunaverse story, set during the second season.