Eli, a 16-year-old girl from the fairly backward nation-state of Ugara, works as a governess to Rinatta and Willin, the post-toddler children of the eccentric Baroness Vasri. When the Baroness books passage on the awe-inspiring Train which dominates the planet's transportation industry, Eli is drawn into a cloak-and-dagger world of intrigue, betrayal, and romance.