This fantasy-sorta book Salamander by David Friedman is excellent, and I’m not saying that because Friedman is also Duke Cariadoc of the Bow, KSCA, OP, OL (basically, the man has hit the level cap in the Society of Creative Anachronism). I’m calling it fantasy-sorta because the magic in it isn’t quite magic; people understand how it works, have theories about it that can be tested via experimentation, and generally can’t use it as a plot device. Plus, the story itself is engaging, and well worth your time. Check it out.