Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Ambivalent novel long on poetry, short on solutions

Tedious novel in the form of nine linked stories shows Mexican life from multiple angles, none too flattering. The crystal frontier of the title is, of course, the U.S.-Mexican border; what matters here is less the border as geopolitical fact and more its impact on the Mexican psyche. The author aims his barbs at both sides of the border; there's little surprising here except perhaps for the portrayal of a disdainful Mexican upper class that couldn't care less about how the other half lives or whether it lives or starves. Book clubs will find this a useful tool for stirring up discussion on the illegal drug and immigration issues whether they read through to the end or not; those who do will be rewarded with a chapter written half in normal prose and half in surreal fragmentary lines of poetry, the effect of which is not unlike sitting through a Tarkovsky double-feature.