As usual, Frances writes very cleverly. It's not clear exactly where Gullstruck Island is, but it's hot enough for jungle and exotic enough for volcanoes. The Lace, an indigenous tribe, have a Lady Lost - a teenager whose mind can float free from its body, taking its senses to far-away places. Or do they? They are not so sure, as she does not seem to speak or interact with them at all, and there is trouble, as the Lost Council is sending an inspector. Then there is a death - followed by several more - and the island erupts in turmoil. The central characters must escape the destruction of their village, then set out on a quest, initially for survival, then for revenge, and ultimately for justice.
Though she makes it clear that there is no single source for her ideas, I felt this book was really bursting with so many themes and allegories - shamans, autism, colonials, religions, pogroms, refuge - and I think that's what makes it her best so far. Some of these turned out to be tangential, and not really what the book was about, but they were cleverly suggested, and you're kept guessing right up to the end.