The magical system of this world is built around grape and wines, with various vineyards producing grapes and wines that have various magical powers and uses. It’s a fascinating concept and when the story delves into the system that Gilman is setting up and how people are chosen and trained in the ways of the magical system, the book really works.
Where the story falls down a bit is in the final third of the novel when it becomes apparent there’s some kind of huge new evil pervading the land and becoming a threat. At this point the novel falls into the standard fantasy tropes and loses some of the momentum it gained and earned in the first two-thirds of the story.
Still, the magical system of this universe and the character work on our hero, Jerzy, is enough that I’ll be looking for the next installment in this proposed trilogy.