Two years ago All the Pretty Horses, the first installment of Cormac McCarthy's "Border Trilogy," rounded up raves from the critics, landed on the bestseller lists, deservedly won major literary prizes (National Book Award, National Book Critics Circle Award for fiction) and proved Scott Fitzgerald wrong.

"There are," said Fitzgerald on one of his gloomy afternoons as an author, "no second acts in American lives." For most of his career, Cormac McCarthy (born in 1933) roamed the literary fringes as a frisky Southern Gothicist, a nephew to William Faulkner, Flannery O'Connor and Tennessee Williams at their most outrageous: In McCarthy's Child of God, for instance, the protagonist develops a liking for sex with dead girls and occasionally wears a wig made out of a woman's scalp; in Outer Dark a sister bears her brother's child. But after Suttree appeared in 1979, McCarthy left his native Tennessee, moved to El Paso, and unexpectedly remade himself into what one might call a Tex-Mex novelist.

In All the Pretty Horses 16-year-old John Grady Cole travels south into Mexico with his friend Lacey Rawlins. Much of that novel's action resembles the most conventional western: long, dusty rides through a gorgeous landscape, an idyll on a big ranch, the doomed love affair with a passionate high-born senorita, a compadre murdered because of his valuable horse, false arrest by unshaven, corrupt Mexican officials, a hellish term in prison and, in the end, a satisfying act of revenge, followed by our hero riding off into the sunset. No doubt some of the widespread success of Pretty Horses derives from its use of these familiar props and costumes. But what makes the novel so extraordinary is, of course, its language.

Languorous yet exact, stately, wistful, occasionally humorous, McCarthy's sentences achieve a kind of epic serenity, as if Homer were to sing of cowboys instead of Achilles. At times, the methodical detailing of men at work—breaking horses, rounding up cattle—echoes the rhythms of good Hemingway, especially the grave, symbol-laden stories like "Big Two-Hearted River." Though its characters are hardly deep thinkers, All the Pretty Horses exudes an air of intimacy and introspection. It possesses an almost sacerdotal gravity. John Grady suffers, endures and ultimately earns that greatest of masculine compliments: He proves himself a serious man. Just so, one might call Cormac McCarthy a serious novelist.

None of the characters from Pretty Horses appears in The Crossing, so one must presume that "The Border Trilogy" is a thematic sequence, three western "novels of education" (unless of course John Grady Cole and Billy Parham team up in the last volume). Like its predecessor, the new book follows the adventures of two young men—the teenaged brothers Billy and Boyd Parham—as they leave home, in this case New Mexico, and travel south to meet their destinies. For McCarthy, Mexico spills over with primitive energy, spiritual mysticism and an unrelenting menace: It is an annealing furnace, a testing ground. In The Crossing the ordeal takes place in four stages: In the first Billy traps a wolf and decides to return her to the Mexican mountains; on their way he and the animal suffer various misfortunes; later Billy and Boyd pursue the horses stolen from their family's small ranch; and in the last section, Billy, unable to enlist to fight in World War II, returns to Mexico to search for his younger brother.

As before, McCarthy's language exemplifies the careful precision of a craftsman, and he is at his best in describing how a professional sets a trap, carries a pack or mounts a horse. "The traps were packed in the splitwillow basket that his father wore with the shoulderstraps loosed so that the bottom of the basket carried on the cantle of the saddle behind him." Such telling and precise detail generates a nearly sensual pleasure, like that one feels in watching an athlete perform with grace and ease.

Less pleasing, however, are McCarthy's purple flights, as when he expatiates about the wolf as "the beast who dreams of man and has so dreamt in running dreams a hundred thousand years or more. Dreams of that malignant lesser god come pale and naked and alien to slaughter all his clan and kin and rout them from their house." Such rhetorical cornpone breaks the continuous revery that prose aspires to. McCarthy works his magic best without flourishes: "The traps leapt mightily. The iron clang of the jaws slamming shut echoed in the cold. You could see nothing of their movement. Now the jaws were open. Now they were closed."

Throughout The Crossing, though, McCarthy always seems to be straining toward a grander level of significance, preferring ideas to things; he jumps for the metaphysical at any opportunity: "The indians were dark almost to blackness and their reticence and their silence bespoke a view of a world provisional, contingent, deeply suspect. They had about them a wary absorption as if they observed some hazardous truce. They seemed in a state of improvident and hopeless vigilance. Like men committed upon uncertain ice." Redeemed by that last sentence, this whole passage belabors, rather beautifully, the same point while skirting perilously close to the pseudo-philosophical.

Indeed, the novel as a whole is criss-crossed with fables, sermons, morality tales and lessons. Billy meets an old priest who talks to him of God's inscrutable ways; he encounters a former revolutionary who has had his eyeballs sucked out of their sockets, and who relates his life of blindness and insight; even Gypsies detail their world-view, while an elegant old cowboy discourses about the meaning of life: "People speak about what is in store. But there is nothing in store. The day is made of what has come before. The world itself must be surprised at the shape of that which appears. Perhaps even God." Some women found Pretty Horses boringly macho, too much a boy's adventure. This one may remind them, in places, of a magic-realist issue of Field and Stream.

To my mind, The Crossing would have been a more effective book had it been leaner, less grandiloquent, more focused on Billy and Boyd. But clearly McCarthy preferred to widen his scope and to take up, somewhat heavy-handedly, the hard question of how one lives in a brutal world. To me, the homely philosophers that Billy encounters sound windy and abstract, especially when compared to the magnificent opening account of the boy and the wolf—though even this goes on too long. Still, it feels wrong to complain too loudly when there's so much to admire: McCarthy's artful reticences, for instance. One never learns the identity of two vicious murderers or the fate of Boyd's Mexican girlfriend. And no one can better describe the unforeseen irruption of violence—"he put up one hand as if to reach for the first of the horses as they came up out of the trees and then his shirt belled out behind him redly and he fell down on the ground"—or the beauty of a naked woman washing her hair in a river:

She bent once more and trailed her hair in the water with a swaying motion sideways and then stood and swung it about her in a great hoop of spray and stood with her head back and her eyes closed. The sun rising over the gray ranges to the east lit the upper air. She held one hand up. She moved her body, she swept both hands before her. She bent and caught her falling hair in her arms and held it and she passed one hand over the surface of the water as if to bless it and he watched and as he watched he saw that the world which had always been before him everywhere had been veiled from his sight. She turned and he thought she might sing to the sun. She opened her eyes and saw him there on the bridge and she turned her back and walked slowly up out of the river and was lost to his view among the pale standing trunks of the cottonwoods and the sun rose and the river ran as before but nothing was the same nor did he think that it would ever be again.

This might be Joyce, an alternative epiphany to Stephen Dedalus's glimpse of the wading girl at the end of Portrait of the Artist.

Above all, despite its occasional longueurs and excesses, The Crossing generates an immense and sorrowful power, especially in its implicit parallels between Billy's relationship to the she-wolf and to Boyd. By its last page the reader will have suffered a great deal—this is not a happy book—and will return, as one sometimes does with a soul-shaking novel, to its opening sentences, saddened by the knowledge of what's to come:

When they came South out of Grant County Boyd was not much more than a baby and the newly formed county they'd named Hidalgo was itself little older than the child … He carried Boyd before him in the bow of the saddle and named to him features of the landscape and birds and animals in both spanish and english. In the new house they slept in the room off the kitchen and he would lie awake at night and listen to his brother's breathing in the dark and he would whisper half aloud to him as he slept his plans for them and the life they would have.

"If people knew the story of their lives," wonders an old vaquero to Billy much later, "how many would then elect to live them?"