Fae began to drift slowly into the land shortly after the birth of the crown princess, Dion ferch Alawn, fleeing a dark threat known only as the Guardians. But that was fifteen years ago, and now there isn't a town in Llassar that isn't populated by or under the control of the fae. Smaller, weaker, and less talented at magic, Llassarians are quickly finding out that there's no fighting the invasion that crept in so quietly and politely. Even the castle isn't free of fae: Those closest to the king and queen are faery advisors. As Dion ferch Alawn returns from a carefully sanitised tour of Outer Llassar, her carriage breaks down and she gets a taste of what the real Llassar has become: Desperate, enslaved, and ripe for rebellion. Getting home safely is just the first problem she faces; the real struggle begins when Dion returns to the castle. Her new knowledge is inconvenient and unwelcome--to declare it, treason.