Fortune's Pawn by Rachel Bach
Summary: (from the author's official site) Devi Morris isn't your average mercenary. She has plans. Big ones. And a ton of ambition. It's a combination that's going to get her killed one day - but not just yet.
That is, until she just gets a job on a tiny trade ship with a nasty rep…
That is, until she just gets a job on a tiny trade ship with a nasty rep…