And I'll nominate a second book,
The Steerswoman, by Rosemary Kirstein. This is another character-driven series, but one with an interesting premise.
From the Amazon description:
Spoiler:
FREEDOM OF INFORMATION
If you ask, she must answer. A steerswoman's knowledge is shared with any who request it; no steerswoman may refuse a question, and no steerswoman may answer with anything but the truth.
And if she asks, you must answer. It is the other side of tradition's contract -- and if you refuse the question, or lie, no steerswoman will ever again answer even your most casual question.
And so, the steerswomen — always seeking, always investigating — have gathered more and more knowledge about the world they traveled, and they share that knowledge freely.
Until the day that the steerswoman Rowan begins asking innocent questions about one small, lovely, inexplicable object…
Her discoveries grow stranger and deeper, and more dangerous, until suddenly she finds she must flee or fight for her life. Or worse -- lie.
Because one kind of knowledge has always been denied the the steerswomen:
Magic.
“If you haven’t read Kirstein’s Steerswoman books I envy you the chance to read them now for the first time.... I think they have a very good claim to be my favorite thing still being written. […] If you like science, and if you like watching someone work out mysteries, and if you like detailed weird alien worlds and human cultures, if really good prose appeals... you’re really in luck.” — Jo Walton, Hugo and Nebula Awards winner, author of Among Others and Farthing.
"[Kirstein] walks the tightrope between fantasy and science fiction with precision and grace... [her] compassion for even minor characters is evident on every page, and her prose is measured and alluring without being overworked." -- Damien Broderick & Paul Di Filippo, in Science Fiction: The 101 Best Novels 1985-2010
This book isn't free, but it's certainly quite reasonably priced at $2.99 (US) (£1.91 UK). Unfortunately, no Audible version of it, however.
Amazon US
Amazon UK
Kobo CA
Kobo US
Note: Kobo versions are couponable!
This series is one you likely haven't heard of, but that you'll thank me for discovering after you read it. They're _intelligent_ books, with strong female protagonists. And a premise that is intriguing and different, but quite compelling.