A story of imperial politics and inheritance in a feudal-Japan-esque setting. It involves a letter of questionable provenience being used to prove that the imperial consort had a lover and her son, who now stands to inherit, was illegitimate. This story felt more historical fiction-y than fantasy (there were a few spirits/ghosts, but they weren't at all pivotal to the story), and reminded me quite a bit of Across The Nightingale Floor, in tone and setting if not in plot. I also figured out several of the twists well ahead of time, but even so, I found the story engaging and enjoyed it overall.