LIFE DURING WARTIME By Lucius Shepard Bantam. 438 pp. Paperback, $7.95

In "Life During Wartime," Lucius Shepard manages to neatly weave the science fiction movement called cyber-punk and Latin American magic realism into a magnificently realized drama of love and moral ambiguity. The feat seems so impossible as to provoke disbelief when imagined -- it is as if cyber-punk maven William Gibson, Gabriel Garcia Ma'rquez and Robert Stone had collaborated on a novel. To say only that Shepard succeeds is to fail to acknowledge the extent to which he makes his disparate elements harmonize and the combination seem natural. And if, in the end, the novel seems to become ensnared in a moral landscape that is the equivalent of the Central American jungle that is its setting, the reader finishes it haunted by its images and Shepard's searing vision.

The novel begins with David Mingolla, a young U.S. soldier fighting in the Central American War, leaving the battle zone with two buddies for a weekend of R and R in Free Occupied Guatemala. "They were not really friends; they had little in common, and under different circumstances they might well have been enemies. But taking their R and R together had come to be a ritual of survival ..." It is sometime in the future. Soldiers in this war wear microcircuited helmets to increase the power of their senses. And if electronic augmentation isn't enough, there are also ampuls of "sammy" -- a drug that gives the user superhuman strength and rots the mind.

Under the influence of "sammy," one of Mingolla's buddies, Baylor, kills a jaguar in a public battle, then goes insane and is taken away by the MPs. The second, Gilbey, deserts, intending to flee to Panama. Mingolla himself meets a woman named Debora, with whom he immediately feels an overwhelming affinity, though he fears she is a guerrilla assigned to encourage American soldiers to desert. He is tempted, but frightened.

This seems for the first few pages to be a war novel, and an extraordinarily powerful one. It soon becomes apparent, however, that Shepard has other matters in mind and intends to stake out other territory. There are stories within stories, such as the Legend of the Lost Patrol, a group of Green Berets who failed to return from a mission and are rumored to live in the jungle, popping "sammys" and dreaming "about the purity of the light, the joys of killing, and the new world they were going to build."

"When I think about the Lost Patrol," Mingolla writes his parents in a letter he knows he will never mail, "I'm not thinking about how sad and crazy they are. I'm wondering what it is they see in that light, wondering if it might be of help to me."

Mingolla's path toward the light, his journey toward knowledge, involves his recruitment into Psicorps, an elite unit of men and women with psychic powers. He is trained and operated on to make him look Hispanic. Remade, he is given his first assignment: to find and kill Debora. His odyssey, Shepard tells us, is one of those "paths that lead to the most profound destinations, to moments of illumination or change, {that} have nothing to do with actual travel, but rather negotiate a mental geography."

As it progresses, the episodes out of which the novel is constructed take on more of a hallucinatory, otherworldly quality. Mingolla learns the extent of his powers and their limits, kills, and penetrates the secret of the Central American War: a centuries-old feud between two Latin American families, the Madradonas and the Sotomayors, who are now seeking a truce so they can continue to control the world.

This sounds fantastic, and it is, but it will be a shame if this book finds an audience made up only of fans of science fiction and Latin American writing. Shepard is that rarest of writers, a true artist, whose concern is to render truth, not trifle with realism. The language throughout is accurate and compelling, each fantastic scene as powerfully seductive as a dream.

The book, and David Mingolla's journey into the heart of darkness, turn out to be about love and those questions that have always plagued humanity: What is it to love oneself and to love another? And how can we do this, being most often aware of our infinite capacity for harm, in a world so fragmented it threatens to make no sense at all?

The reviewer is an assistant editor of Book World.