[Something twists in Persephone's face, an emotion struggling to the surface, but she turns away for a moment in a gesture to the train]

Well, from my experience, we are expected to do chores on the train and once a month or so, we arrive on a world and help them with some trouble they have. The last world was dealing with an invasion...from another world. Before that, I think someone said it was stopping someone from freezing a village? The scale of the problems seems to vary.