THE CRYSTAL FRONTIER: A Novel in Nine Stories.<i> By Carlos Fuentes</i> .<i> Translated from the Spanish by Alfred MacAdam</i> .<i> Farrar, Straus & Giroux: 266 pp., $23</i>

“The Crystal Frontier,” a novel in nine stories, explores the deceptively transparent border between Mexico and the United States. Carlos Fuentes’ 19th book is amphibian fiction--a form hovering between long and short prose--an acute political novel and a cosmopolitan, intergenerational saga.

Fuentes crisscrosses the international threshold, driving air-conditioned limousines and wading through freezing river water, with members of the extended business and blood clan of Leonardo Barroso, a northern Mexican millionaire. At first the lyrical, suspenseful, picaresque pieces seem oddly disparate. The nine stories concern Barroso’s family, financial partners, friends of friends, even his almost anonymous factory workers. Their mutual bond on the illusory “Crystal Frontier” is revealed to be as inextricable as it is initially invisible.

Charged by a fierce current between intellect and art, Fuentes writes within a tradition of “the novel of ideas.” His book deals with Spain’s genocide of native peoples, wars between Mexico and the U.S., the murky drug trade, PRI government policies and the shortsightedness of NAFTA and Proposition 187. Crucial to Fuentes’ success is an active engagement of readers’ imagination, intelligence and moral complicity.

“The Crystal Frontier” is a segmented novel about community and the individual within the community. A protagonist from one story appears in the wings of the next, then leaves for three chapters, only to be strangely pivotal in a later story. Fuentes’ characters fade in and out of focus, provoking readers to see characters (and themselves) in complicated, shifting social contexts.

At the novel’s center is the ruthless, extravagant life and the sudden, violent death of Barroso, who earns big profits from directing human traffic across the border. The charming, 50-year-old businessman has the ear of influential American tycoons and politicians (Robert Reich makes a cameo appearance as U.S. secretary of labor). While Barroso (whose surname means “muddy” in Spanish) is profligate in entertaining his daughter-in-law / lover, he is also cannily circumspect about public exposure. “Neither he nor the rich politicians ever appeared [in Fortune] . . . because none of their businesses had their names on them: they hid behind the seven veils of multiple partnerships, borrowed names, foundations. . . .”

Barroso controls the fate of strangers and people he hardly knows, like the young Juan Zamora, an employee’s son, for whom he arranges a Cornell medical school scholarship. The bright, sensitive young man is confounded (and almost destroyed) by his encounter with American parochialism and entitlement. He is housed with a rich family whose privilege is constantly matched by their ignorance as they awkwardly treat the impoverished Juan as if he were a Spanish aristocrat. “Charlotte never called Juan Zamora Mexican. She was afraid of offending him.”

Fuentes mingles generations, classes, geographies; sojourners move from Juarez, Mexico City, Tijuana, Juchitan, Compazas, Nogales and Mexicali to San Diego, El Paso, Los Angeles, Houston, Chicago and New York. They include Barroso’s young lover who shops for designer clothes in Texas, a middle-aged housekeeper trying to buy her husband’s release from an Illinois jail, a disgruntled taxi driver who harasses tourists, overworked mothers who slog in Barroso’s profitable maquilas, or border factories.

The title story follows 26-year-old Lisandro Chavez from Mexico City to New York City as a “weekend contract” janitor. Barroso is the entrepreneur. Fly them in; fly them out and avoid American labor costs. Chavez’s middle-class family has crashed on the Mexican economic roller coaster of the 1980s and ‘90s. “. . . I have to join the sacrifice of all, join the sacrificed nation, ill-governed, corrupt, uncaring. I have to forget my illusions, make money, help my parents, do what humiliates me least, an honest job. . . .”

As Chavez washes windows in the atrium of a 40-story Manhattan skyscraper, Audrey, an advertising executive, settles at her desk, hoping to catch up on her work on this quiet Saturday. “Lisandro had carefully cleaned the first window, that of Audrey’s office, and as he removed the light film of dust and ash, she had begun appearing, distant and misty at first, then gradually closer, approaching without moving, thanks to the increasing clearness of the glass.” The two silently communicate with eye contact, gesture and the spelling of words (backward) on the transparent wall between them. “He placed his lips on the glass. She didn’t hesitate to do the same. Their lips united through the glass. Both closed their eyes. She didn’t open hers for several minutes. When she did, he was no longer there.”

While the long narrative of “The Crystal Frontier” is cleverly structured, the stories vary in quality. Fuentes sometimes scrawls prosaically, forfeiting fresh, distilled language to flat, cerebral statement. Description slips into cliche and stereotypes about Barroso, who “girded his loins”; about the slick Chicago lawyer, who “nervously fingered the knot of his Brooks Brothers tie”; and about the WASP aristocrat reading “the number-one book on the New York Times bestseller list, a spy novel that happens to confirm his paranoia about the red menace.”

“Rio Grande, Rio Bravo,” the passionate final chapter, is a tour de force historical opera, staging Mexican history from early Indian settlement to the contemporary dramas of Barroso and company. One utopian vignette introduces Fuentes’ alter ego, the long-haired Jose Francisco, who is halted by Mexican and U.S. guards for transporting literature across the border. “The manuscripts began to fly, lifted by the night breeze like paper doves able to fly for themselves. They didn’t fall into the river, Jose Francisco noted; they simply went flying from the bridge into the gringo sky, from the bridge to the Mexican sky, Rios’ poem, Cisneros’ story, Nericio’s essay, Siller’s pages, Cortazar’s manuscript, Garay’s notes, Aguilar Melantzon’s diary, Gardea’s deserts, Alurista’s butterflies, Denise Chavez’s thrushes . . . and Jose Francisco gave a victory shout that forever broke the crystal of the frontier. . . .”

Throughout the novel, Fuentes plays with the tensions between durability and fragility, between exposure and protection, between visual transparency and physical barrier, as well as with other material and metaphorical properties of glass. In one story, Barroso’s son imagines himself a Christ-like figure in a crystal coffin; in another, Barroso’s politically progressive brother is portrayed as Cassandra screaming in a bell jar. Fuentes finds his crystal frontier in the infrared goggles of the U.S. Border Patrol, in the safety peepholes of urban apartment doors, in Manhattan’s high-altitude windows and in the almost transparent body of a rich Chicago dowager. The border weather is always mercurial--baking heat, raging storms--but rarely does a rainbow get refracted on either side of the crystal frontier.