It's difficult to be a Warrior Queen in an age of Legislative Princesses.
Luna has found a place in Canterlot society, braved social awkwardness and even managed to legislate unpopular changes, but she finds herself ill at ease with the day to day running of a government. She craves adventure and excitement, but perhaps the vicarious enjoyment of same through an evening of theater will do.
Poor princess. Nothing ever seems to be quite so simple. A murder mystery might well become... two.
Starring a Canterlot cast, new and familiar, international espionage, murder, and Luna doing her best to turn everything into a story of Hay-Cules Pear Roll.
(As this is a sequel to the previous Night Princess And... stories, it diverges from the show canon shortly after the beginning of Season 5.)