Excellent adventure writing; it's a bit slow to build up but the final showdown on the rails through the Rockies is campy steampunk excitement. The protagonist being a Confederate nurse counts against it, unfortunately; her journey to racial tolerance includes her thinking but not saying (and thus telling the readers but not the Black character) the n-word about a Black character. I say, if she wouldn't say it to a Black person in 1887, then surely the author should not say it to her readers.