In a richly imagined future 250 years from now, rising sea levels have reduced Britain to the Rhine Delta Islands, its traditional culture maintained only in a few self-isolated fenland conclaves by residents dubbed—scornfully but, as it turns out, significantly—“Oysters.” The discovery of a skeleton on Oyster territory precipitates a cascade of strange incidents, from a series of staged “riots,” to disappearing books, and a supposedly public outcry against all study of old human remains as links to racism and nationalism. To archaeologist-in-training Merrick Korda, it’s all tangled up with his own English heritage, and also the small excrescences that he had found within that skeleton—“moss pearls.” A suggestion that these used to be deliberately “farmed” leads Korda to attempt a proof by growing one in his own body. Intrigue, murder attempts, pursuit across potentially deadly boglands, and weeks of exquisite pain ensue—but so complex are the wheels within wheels here, so murky the motives of several of the characters that, despite lengthy explanations, there’s no clear sense of resolution at the end. The author offers plenty of social and human commentary, but as a satisfying story, it ultimately misses its mark. (Fiction. YA)