Three years ago, Claire Vaye Watkins exploded onto the literary scene with "Battleborn," a superb collection of short stories that artfully intertwined the complexities of human relations with the mythology and topology of the American West. For her eagerly awaited debut novel "Gold Fame Citrus," Watkins once again affords people and place equal status. The result is a work of admirable scope and enviable talent.

Watkins wastes no time in introducing her terrifying conceit. Southern California has been hit by a "drought of droughts." Cities burn or are besieged by "sandalanches."

In parched Los Angeles, Ray and Luz are holed up in a starlet's abandoned mansion, hiding from militias, distanced from persecuted "Mojavs" and surviving on rationed cola and scavenged food. Ray is an AWOL soldier from the forever war, Luz a former poster child for the Bureau of Conservation. One night at a rain dance they come upon a neglected, possibly abused, 2-year-old girl called Ig and take her under their wing. Then, when life in their "desiccant city" becomes unbearable, the three of them embark on a perilous cross-country journey eastward.

Disaster strikes when they run out of gas. Ray leaves Luz and Ig to get help. But he fails to return, and hours without water in searing sun turn into days. Just when Luz and Ig are on the brink of dying from dehydration, they are rescued and taken to a colony in the desert. But how much of an oasis of calm is their newfound sanctuary? And what has happened to Ray?

Watkins has crafted a powerful, innovative and hallucinatory novel from a bleak yet all-too-real vision. Her landscapes feel primordial and postapocalyptic. Each is brilliantly mapped: from "the failed experiment" that is California, a onetime El Dorado that promised hucksters and pioneers the "mirage" of "gold, fame and citrus," to the amorphous Amargosa, a self-perpetuating city-devouring dune sea. We meet squatters, hagglers and looters, "hoodwinked dreamers" and "ghost detainees," plus a dowser called Levi and a prisoner called Sal, who, individually and temporarily, restore Luz and Ray's faith in humanity.

The novel bursts with grand ideas and original scenarios. However, it becomes distinctly uninvolving every time Watkins deviates from Ray and Luz to give case studies of secondary characters, or to meditate upon matters geological, historical and ecological. More critically, it is during these interludes that Watkins' fluid prose turns into an unregulated torrent: no plot spurts, only splashy stylistics.

When we are back with one or both of the main characters, Watkins' language is less self-conscious and more functional, designed to quietly captivate and resonate while making us feel for Ray and Luz as they endure thirst, fear, separation, strained love and unknown environments. It is in these less showy moments that we can enjoy this novel for its gutsy inventiveness and its skilled portrayal of a relationship put to the ultimate test.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. He lives in Edinburgh, Scotland.