Tazir has been plying the sealanes in her trade ship for many years, and is facing the same challenges all her competitors are, in these hard days when the Dragonships have started ravaging those some sealanes and the communities near them. She has no interest in anything other than keeping her ship and crew afloat and profitable--even if only barely--and no interest in challenging the Dragonships.
Shina is a young woman fleeing something, probably an unwanted marriage, but she has the money to hire the ship to make an unlikely journey, and that's what Tazir and her crew care about. That's the business they're in. It's no fault of theirs that they don't know what her real purpose is, or that they start to like her quite a bit.
Shina is an apprentice Windspeaker.
A major source of the Windspeakers' power has been stolen, and for reasons that gradually become clear, only an apprentice can recover it for them. Shina is leading Tazir and her shipmates into the heart of what they want to avoid.
Foter unfolds her world and her characters in measured layers, making it and them fascinating and compelling. I hope there's more in this world. Highly recommended.