He never came all the way home. Even those time zones of the soul, his circadian rhythms, remained fixed by a clock half a world away. Long ago his habit had been to end the day with evening walks beneath the tamarind trees lining Saigon's streets. Then the walks turned to solitary dawn patrols under Washington's baleful oaks. He worked Saigon time. He slept Saigon time.

Over the years, early-risers on Klingle Street in Neil Sheehan's quiet Wesley Heights neighborhood caught an occasional glimpse of his lean and ascetic figure ending his day with the relentless morning marches. The writer, they called him at first. Then the recluse. Then the hermit. He seemed lost in time and space. Nothing told as much as his face. Even in the early light the eyes burned with the intensity of youth. The other features had yielded to middle age and taken on the soft pallor of a man too long in captivity.

Some of his friends called him the last casualty of Vietnam. But that wasn't quite right. Neil Sheehan was the war's last prisoner.

Tolstoy labored six years writing the Russian epic War and Peace. Sheehan spent 16 years shut away like a medieval monk, chipping away at the riddle of the war others wanted to forget.

The ordeal is over now, his book, A Bright Shining Lie, finally on the shelves, its dust jacket beckoning to the best-seller lists. It is a remarkable tale, the story of one complex soldier's hidden life and his deadly obsession with Vietnam. Long before publication, A Bright Shining Lie became an event, acquiring a mystique among the cognoscenti in New York and Washington. But the mystique cloaks the writer even more.

At the house on Klingle Street, it is 3:30 on a hot summer afternoon, and Sheehan has just come downstairs clutching the day's first cup of coffee. Old habits are hard to break. He is 51 years old now, graying, and wearing a tropical shirt with bush-country epaulets, part of him forever frozen in the Pax-Americana boy-wonder days he once knew in Asia. Across the living room is another reminder of days gone by. On a pedestal sits a golden Buddha, eyes all-seeing, smile inscrutable.

The talk comes easily of the good things that have happened lately -- his book's New Yorker excerpts that drew rave reviews, the $150,000 sale to the Book-of-the-Month Club, the six-figure purchase by a British publisher, movie producers hovering, paperback auctions looming. Random House, the New York publisher that stayed with him all these years, has set a first printing of 100,000 -- best-seller range -- and Sheehan soon will be on tour, out of his prison.

His eyes drift across the room toward the all-seeing Buddha.

Sixteen years . . . EIL SHEEHAN, THE YOUNG WAR correspondent who had given President Kennedy fits in the first innocent days of Vietnam, the world-famous New York Times reporter who had obtained the Pentagon Papers, for 16 years this Neil Sheehan seemed to drop off the face of the earth. His work hours had turned toward night, his sleep toward day. Friendships faded and broke. He began passing up the weddings, the goodbye parties and the reunions, even the funerals. Daytime events would steal from his sleep, evening events from his work. He was a man obsessed. Once, early on, he tried to break the pattern and went out to dinner with friends. He got sick and had to leave. Even at home, the anxiety clawed at him. He doubled up with stomach pain and survived on chicken soup.

His recollection became that his wife, Susan, stopped giving dinner parties a few years ago. Susan recalls more clearly: She stopped the night Ronald Reagan beat Jimmy Carter.

In the beginning their daughter Maria was 5, Catherine just 3. Susan, also an accomplished writer, adopted the same nocturnal schedule as her husband -- for how long could this possibly go on? The girls had breakfast at 8 in the morning, the parents at 3 in the afternoon. Dinners out came twice a year, at Chadwick's and Hamburger Hamlet. Entertainment became "Masterpiece Theatre." Once, they almost made a family vacation, right down to air tickets and condo reservations. Then Dad pulled out, too tied to his grand obsession. The operative words around the house, the words that ended each sentence, became "when Daddy's book is done." The kitchen will be repaired . . . The shower will be fixed . . . The family vacation will come . . .

. . . when Daddy's book is done. Maria and Catherine are grown now and gone from home.

Sixteen years . . .

"I made my own little quarry," Sheehan says, "and I stayed busy with my hammer and chisel. Yeah, I began to feel like a monk. Obviously, I'm something of an eccentric with an obsessive personality. Let's say I'm an eccentric person."

The riveting eyes pull away from the serene Buddha.

"My God, it was grim," he adds quietly. "They were such grim, grim years. It was a much longer journey than I ever expected to travel." CROSS THE POTOMAC, ON JUNE 16, 1972, Arlington Cemetery prepared itself for a ritual now too well practiced. Neil Sheehan arrived late and stood in the back of the chapel. It was, as he would write much later, a funeral to which they all came: Gen. William C. Westmoreland, the believer who would forever believe; Daniel Ellsberg, the believer who turned apostate; the last of the Kennedys, finally convinced of the folly; Joseph Alsop, the Establishment columnist who once accused Sheehan of undermining his country's security; the widow, the fatherless children, all the diverse players from a sad decade fast fading.

And the dead soldier. John Paul Vann had been an enigma, for only an enigmatic man could have drawn such a cross-section of Washington's Vietnam generation to Arlington. Over the past 10 years he had inspired and aggravated them all, hawk and dove alike. In Vietnam he seemed blessed with magic. He took terrible risks, taunting his enemy by driving alone into the jungle at night, and his very aura made men take chances they normally would find foolish. Now he had died in a random helicopter crash, an accident, the magic gone, the last vestiges of American magic gone with him. Vann's death, like his life, had been as contradictory as his country's self-certain do-goodism turned foul. His funeral would be, too. As he was buried, riflemen fired the traditional military volleys of highest honor. A military band played the '60s antiwar song "Where Have All the Flowers Gone?"

Sheehan left Arlington that day certain he had watched America bury more than John Vann and haunted that there was something he still needed to bury, too.

"I had a feeling," he said, "that we were burying an era with this man. We were ending this high point of a great power when those who live in it -- Englishmen in the 19th century or Americans in the 1960s -- are filled with such self-confidence and total sense of righteousness that they can take life or spend it in their own cause with absolutely clear consciences. We were burying this with John because Vietnam had shattered all of that, and it never would be the same again." DECADE EARLIER, ON A STEAM- bath April day in 1962, Cornelius Mahoney Sheehan, green as Irish grass, first stepped off a plane in Saigon, the new $100-a-week correspondent for United Press International. The newcomer was 25 years old, a poor kid from an Irish farm family in Holyoke, Mass., still speaking in a slight brogue that even a Harvard scholarship had been unable to drum out of him. Nothing about this young man -- just out of the Army on his first full-time job -- hinted that he could come home famous, one of a new breed of skeptical, aggressive and controversial war correspondents.

Nor did the obscure little war in the backwaters of Southeast Asia offer much promise of front-page fame. South Vietnamese soldiers still trudged off to battle with squawking ducks hanging head down from their gun belts. Lumbering old American planes of Second World War vintage sometimes returned from secret sorties with arrows piercing their aluminum hides.

This was changing, and faster than a secretive American government wanted its public to know. The count of American military advisers in this far-off land had risen from 800 the year before to 3,200 as Sheehan arrived. By the following year it would be 11,200, and then it would rise exponentially beyond anyone's dreams.

But now it remained a war the tiny band of correspondents could cover by taxi, picking up a tip in a garish French nightclub and racing off in chase of elusive battles in tiny Renaults or rusting old French Citroens.

"I thought the war was a glorious adventure," Sheehan said. "First of all, we all believed in the American cause. We believed totally in the American cause. When I went out on my first operation and there were bullets, I was thrilled. Some people got killed around me. Small arms fire. The South Vietnamese got scared. I looked at them and said, 'Look at how fearful they are.' I wasn't afraid. We were winners; we were invulnerable; we were right."

Sheehan became entranced. Vietnam seemed so worth saving. In Saigon, women of remarkable Asian beauty -- tiny, porcelain, ephemeral images of perfect grace -- wafted past. He fell in love with one, or perhaps it was with the exotica of it all, and she charmed him with stories about the concubines her wealthy grandfather kept. In city streets he watched Buddhist monks, with heads shaved and lithe bodies cloaked in saffron robes, move silently through a babble of Hindu money-changers. Down narrow Asian alleyways, expatriate Chinese with three-strand beards and opaque eyes beckoned the way to undreamed ancient pleasures. Vietnam cast a spell that could last a lifetime.

Sheehan became only the third full-time American newsman in Saigon. The others were Malcolm Browne of the Associated Press, a 31-year-old unknown also destined for fame, and Homer Bigart of The New York Times. At 54, Bigart already was a legend. A crusty old pro who had been shot at in anger in some part of the world for each of the past 20 years, he was perhaps the most famous war correspondent of the age, and he had only one contradictory trait: When angry, he stuttered. Sheehan worshipped him.

Two weeks after arriving, Sheehan got his first hot tip -- 200 Viet Cong guerrillas dead in a battle near the town of My Tho, 40 miles south. With the certainty of an innocent, he ran with it, driving Bigart's story onto the back pages.

Sheehan had just fallen asleep when the phone rang. "Sh-sh-sheehan," the menacing voice began, "g-get dressed. We are going to My Tho. You just got me a r-r-rocket from New York. There b-b-better be 200 b-b-bodies down there, k-k-kid."

There were 12 bodies at My Tho. Sheehan filed what is known in the trade as a rollback. "And it was a helluva rollback," he recalled. "I was mortified and certain I would be canned." Bigart just laughed. "Don't feel so bad about it, kid," he consoled, the stutter gone now. "Just don't let it happen again while I am here."

Bigart stayed in Vietnam only a few months longer, but Sheehan followed him everywhere he went. There was a doggedness about him even then. When David Halberstam came in as the new Times man, Bigart had left him a note: "The kid from UPI is going to be very good."

Over the next year, the kind of year that could provide the seedbed for any young man's obsession, the nice little war became not so nice and Sheehan quickly shed his rookie status. He and Halberstam, 2 1/2 years his senior and cockily ready to make his own mark in the world, became bosom buddies. They quickly found that the American command in Saigon was a dry hole for news, given to a deadly combination of secrecy, false optimism and papering over battle defeats as victories.

So Sheehan and Halberstam picked up their tips in Saigon dives like Cheap Charley's, a 50-cents-a-plate Chinese joint, or La Cigalle's, an intrigue-filled nightclub run by a tough Corsican, and jumped into their little Renaults for the run down the narrow macadam highway to My Tho, the scene of Sheehan's first rookie mistake.

My Tho sat in the heart of the rice-rich Mekong Delta and the heart of the war. It also served as the headquarters for a remarkable American military adviser, a 37-year-old light colonel who seemed destined for general's stars, John Paul Vann.

Gung-ho, full of Yankee can-do optimism voiced in the raspy hill-country accent of rural Virginia, Vann immediately impressed the reporters. He seemed a '60s military classic, a soldier immersed in the newly captivating theory of counterinsurgency warfare. This war would be won with a knife and a rifle, he said, not the cruel foolishness of thousand-pound bombs raining down on innocent peasants.

But it would not be won the way corrupt South Vietnamese army commanders were fighting. They were taking bribes, standing off, avoiding showdowns, shelling villages. "These people may be the world's greatest lovers," he said, "but they're not the world's greatest fighters." Still, they could be. And why not? Their own brothers, the Viet Cong guerrillas, fought like tigers in defeating them. The key was to get the commanders to fight his way.

As certain of himself as he was of his cause, Vann had a devious plan. He would find a battle the commanders could neither avoid nor lose, then play on their newly inflated egos to fight his way.

Vann and his battle, outside an obscure hamlet called Ap Bac, would have an indelible effect on Sheehan. Just how indelible, he said later, he "had not a glimmer of an idea" during those early conversations.

The first news about Ap Bac reached the reporters on the streets of Saigon on the afternoon of January 2, 1963. Sheehan grabbed the sketchy reports and rambunctiously made a perilous nighttime drive down Highway 4. By daybreak he was at the battlefield. The sight sickened him.

Sprawled in the paddies, where they had lain untended all night, were the bodies of 80 South Vietnamese soldiers. Angry American advisers prodded reluctant survivors into retrieving their own dead. Out of respect and sorrow, Sheehan pitched in, crossing himself and vomiting as he covered one mangled body after another. The grim task over, he was preparing to leave when he heard the sudden horrible whine of shrapnel and threw himself into the muck. A far-off South Vietnamese commander had begun shelling the village, occupied now only by his own men and a handful of Americans. Four more Vietnamese soldiers were killed and 10 wounded. "I never saw any glory in war again," he said, "and I never again went into a battle unafraid."

Vann was furious. He had, indeed, set up a battle impossible to lose, surrounding 200 guerrillas with a force several times as large. But the South Vietnamese commanders had held off, allowing their men to be methodically slaughtered and the guerrillas to escape in the night, leaving behind three dead. "A miserable goddamned performance, just like always," Vann snorted, kicking a high-laced airborne boot into bloodied paddy soil.

The stories that Sheehan and the others wrote in the next few days spread news of a major defeat across American front pages. The official report sent to Washington, however, was different: The overwhelming defeat at Ap Bac had become another papered-over South Vietnamese victory.

Three days later, the commander-in-chief of the Pacific, Adm. Harry Felt, arrived in Saigon and was met at the airport by the reporters. At the admiral's side stood Gen. Paul Harkins, the ever-optimistic commander of the American advisory force.

"I'd like to say that I don't believe what I've been reading in the papers," Felt announced. "As I understand it, it was a classic Vietnamese victory, not a defeat."

"That's right," echoed Harkins, who had not visited the battlefield. "A Vietnamese victory. It certainly was."

Suddenly the imposing battle-starred admiral turned toward the young rookie reporter from UPI. "So, you're Sheehan," he said testily. "You ought to talk to some of the people who've got the facts."

Sheehan bristled. "That's right, admiral," he fired back with hair-trigger speed. "That's why I went down there every day. You might try sending your own people down."

Sheehan's stories took on a new bite after that. The correspondents became disbelievers, not in their country's cause but in their country's leaders.

In April, Vann left Vietnam. The correspondents saw him off at the airport, giving him a silver cigarette case engraved with their names and the inscription: "Good Soldier, Good Friend." He quit the Army that summer.

By then Saigon was blowing apart at the seams. The story exploded into daily front-page news and brought droves of new reporters into Vietnam, most of them well-briefed by the Kennedy administration. The administration was in a strange position: Publicly it tried to undermine the Saigon correspondents' credibility and even their patriotism because of their pessimistic reporting; privately it was more pessimistic than the reporters and had begun plotting the overthrow of America's handpicked South Vietnamese leader, Ngo Dinh Diem.

Suddenly, the young turks found themselves up against some of the best-known names in their own profession. Columnists Joseph Alsop and Marguerite Higgins, close friends of Kennedy, ripped into them, Higgins calling them "the young rover boys" who "would like to see us lose the war to prove they're right." Time magazine fired the heaviest fusillade, printing a full-page attack disputing their accuracy and their service to their country.

With the assault on the young correspondents coming from all sides, their bosses grew edgy. President Kennedy went so far as to personally ask the publisher of The New York Times to relieve Halberstam. The Times held, nervously. Sheehan was in deeper trouble.

By October, UPI began killing Sheehan's stories, including one that implicated U.S. Ambassador Henry Cabot Lodge in the plotting against Diem (which turned out to be accurate). Sheehan yowled in protest. His bosses insisted he was tired and acting too emotionally. Come out to Tokyo for a rest, they said. Sheehan was flabbergasted. A rest? He had been here 18 months and the government was about to fall, with the United States doing the pushing. Come out for a vacation, came the reply, or be fired.

Angrily, Sheehan left for a one-week vacation at the end of October. The forced vacation would become part of the legend, too. He left behind some classic Sheehan footwork, convincing one of the Vietnamese plotters to tip him off to the imminent coup d'etat by sending out a coded message: "Please buy me two bottles of whiskey in the PX." The message would go to Halberstam or Ray Herndon, his new UPI assistant, who would send a second coded message to Tokyo.

On November 1 Sheehan sat eating a late dinner at the Tokyo Press Club when he got an urgent call from the UPI office. The wire ticker was reporting fighting in the streets of Saigon. His heart sank as he raced over to the office, where he dug desperately through the message spike. Deep down he found the cable from Herndon: "Please buy two geisha dolls, Kyoto style." It had arrived 19 hours earlier.

"Oh, Christ," Sheehan moaned.

"But what does it mean?" asked the young message clerk.

"It means a coup, you goddamned fool," the old pro from Saigon shot back. "It means a goddamned coup." HE NEW YORK TIMES HIRED Sheehan away from UPI in 1964, not long after he missed the coup. By then he had become known as one of the "fearless threesome" -- Halberstam, Browne and Sheehan. The romance with his Vietnamese girlfriend had ended, and during a New York breaking-in period he met and fell in love with another young writer. He and Susan were married in Jakarta, a way-station assignment for Sheehan on his way back to Vietnam and a war quite different from the one he had left. It had become very big and very American.

He bumped into John Vann in Saigon. Vann had gone back as a civilian. Like a moth to the flame, Sheehan thought. Vann had taken a low-level job at the Agency for International Development, but, as the war grew, he would rise to the civilian equivalent rank of general. They saw each other off and on, gradually more off than on. John had his compulsion. Compulsions made Neil nervous; compulsions were dangerous.

The Sheehans left Saigon in 1966, The Times giving Neil the choice assignment of the Washington bureau, Susan pregnant with the first of their two daughters and the first of her books, too. They were still in their twenties.

The antiwar movement had begun to move into high gear, and, at first, some of the folklore was awkward to live with. Myth has a way of enhancing reality. The protesters lionized the early Saigon correspondents as the first of the antiwar rebels. But that wasn't true. "I believed," Sheehan said. "We all believed. I believed for a very long time."

By 1972, however, Sheehan had come full circle. Within the past year he had written two passionately antiwar pieces that, observed his colleague, Harrison E. Salisbury, brought into question whether American presidents and generals should be "placed in the dock and made to stand trial for their lives" for war crimes.

But the ultimate legend-maker had been the Pentagon Papers. Sheehan rooted out the secret government study about the deceit and self-deception that had lured America into Asian quicksand, and the myth became a new reality.

As it had a decade earlier, the government responded with a vengeance. Once again, Sheehan's honesty and patriotism were questioned. A federal grand jury, looking for violations of the Espionage Act, investigated him. Federal officials subpoenaed his bank records and questioned his friends and neighbors. In the year after the Papers' publication, Sheehan did little work, spending his time with lawyers and preparing himself for the day when he might have to explain to his two young daughters why their father might go to jail.

In the reverse-image world of power journalism, of course, the assaults were badges of honor, the legend not only intact but enhanced.

Still, Sheehan's friends worried about him. He had been so carefree and ebullient during those early days in Vietnam. Now it was as if some dark Irish cloud had settled over him. Salisbury thought he had turned dour at a time when he should have been sitting on top of the world. Halberstam found him pessimistic, even morose.

Beneath all the career glitter, Sheehan's years at The Times had not been happy. By sending him to Washington, the newspaper had hoped to broaden his view from Vietnam to the world. But Neil Sheehan didn't want the world. Whatever the assignment, he twisted back toward his own bewitchment -- Vietnam. He tried to return in 1968, during the tide-turning Tet offensive, but the newspaper turned him down. He suffered badly in The Times' often brutal internal politics. He also was dreadfully slow, a chaser of the last fact. If his admirers saw this as dogged and persistent, his editors saw it as abominably endless and obsessed. Even after the incredible triumph of the Pentagon Papers, he was not their favorite.

He had had his professional disappointment as well. Twice he had been passed over for journalism's highest honor, the Pulitzer Prize. The first time it was rather blatant, when Halberstam and Browne shared the award for their 1963 coverage from Vietnam. Now it had happened again. The prize went to The Times for covering the Pentagon Papers but not to Sheehan for uncovering them. Halberstam was outraged, complaining that it was "inconceivable" that Sheehan had been passed over in Vietnam and wondering if the second rebuff was "a way of getting even with an audacious reporter."

But Sheehan's malaise ran deeper. In 1972 President Nixon was withdrawing the last of the American troops from Vietnam. The story was fading from both the front pages and the American consciousness. "Something was unfinished in me," he said. "It was eating at me. I had to get this thing out of my system. I needed to leave something behind." After John Vann's funeral, the need nagged worse.

By the end of the summer Sheehan had decided to write his book. He saw John Vann as the personification of America's long and painful commitment to Vietnam. It did not occur to him that Neil Sheehan might come to represent America's long and painful recovery. HE FIRST 18 MONTHS WENT well. It had been a classic Sheehan effort, the kind, Susan recalled, that "would have had them beside themselves" down at The Times. He had written nothing. He had, instead, dug -- and dug and dug. Into John Paul Vann's family history. Into Vann's personal and military records. Into the recollections of his Vietnam friends and colleagues. Into the great quagmire of the war itself. He had to know everything.

Before the ordeal was over Sheehan would interview 385 people, some as often as 10 or 15 times. He would use 640 tape cassettes and 186 note pads. He would pore over millions, perhaps, literally, billions of words in arcane documents and hundreds of books. He would study hundreds of maps and battle coordinates.

It would be easy, trying to understand Sheehan's compulsion, to take it as a search for the ultimate truth, a quest for the Holy Grail.

"That would be the Hollywood version of what happened," Susan said. "But it wouldn't be true. I remember one time he showed me a sketch of the Ho Chi Minh Trail, and I always had this vision of a line, not a straight line but a line curving through the mountains. But it was a skein of thousands of miles and Neil had to figure it out before he could go on." Then she laughed and said Robert McNamara might have saved a lot of bombs if he had studied it as thoroughly.

Sheehan plumbed every depth. If he had to know how many fingerling jungle paths fed into the Ho Chi Minh Trail, and there were thousands, he also had to know how many women John Vann had slept with, and there were as many as there were jungle paths. He had to know the depth of America's self-deception and delusion just as he had to know the depth of his friend's, and John Vann's ran at least as deep.

At the funeral Sheehan had already concluded that Vann was an archetype in America's grand delusion: "He had exemplified it in his illusions, in his good intentions gone awry, in his pride, in his will to win." But it was more than that. The awful sadness, the great tragedy, had come in Vann's gradual self-betrayal, just as it had come in his country's. He had gone there as a soldier determined to win, but win with the least amount of hurt, the least amount of suffering for the people trapped in the cross fire. He had died determined to win, but win regardless of the hurt, regardless of the innocent people.

Vann stayed 10 years, almost the duration, and three of his statements describe the terrible deconversion of one man, one country:

1962, during the little guerrilla war: "This is a political war, and it calls for the utmost discrimination in killing. The best weapon for killing is a knife. The next best is a rifle. The worst is an airplane and after that the worst is artillery. You have to know who you are killing."

1965, after watching the first American combat troops torch a village on television: "If this is to be our policy, then I want no part of it and will not be associated with such an effort."

1972, as the end neared, his and the war's: "Any time the wind is blowing from the north where the B52 strikes are turning the terrain into a moonscape, you can tell from the battlefield stench that the strikes are effective."

So the theme was clear to Sheehan as early as the funeral. The digging, the relentless digging, only muddied it. Digging made Sheehan's hole ever deeper, simplicity at the surface, complexity at the bottom. John Vann's compulsion, Sheehan found, was driven as well by other demons, other needs. Vann's story was no more simple than America's surface compulsions. The story grew more complex and better. Sheehan dug deeper.

"This was a war we were about to lose and soon would want to forget," he said. "I had a very keen sense that a lot of this war existed only in people's minds and it had to be captured before they moved on. I also had a very keen sense that South Vietnam was going to disappear."

Sheehan started with a moderate $40,000 advance from Random House and a $10,000 fellowship from the Guggenheim Foundation. Twice, in 1972 and 1973, he returned to Vietnam.

Clearly, Sheehan had to go for his own sake as well. But he had become very frightened of the place, certain he was tempting the gods, as Vann had. "I was very scared at the end of each of my earlier tours," he said. "I was certain I was going to be killed if I stayed. You can take so much of war, a year, two years, and then it gets to you. I would retch in the morning when I woke up." He pauses. "But I had to go. Obviously."

This Vietnam was like nothing he had seen before. In 1962 it had been an adventurous little war by taxi, more dangerous in the streets of Saigon. In 1965 cocky American troops had come in, and it was search and destroy, easy to get destroyed yourself. But American troops never lost, did they? Now it was a futile cause, no cause at all, with sullen American boys, feeling wasted, often wasting their own leaders as well, rolling grenades into officers' tents at night.

Sheehan, who retains a strong military bent, was horrified. And scared. At an American military camp he watched a Vietnamese woman come in unchallenged to visit her boyfriend and thought: "Hell, anybody could come in here and shoot us all in our beds." He rode into another camp with an American major, and the guard didn't salute. "I said, 'Hey, that guy didn't salute,' and the major just shrugged. Hell, he was afraid of his own men."

Finally, he had one last chore -- to see the isolated spot in the countryside where John Vann had died. His Army escorts were less enthusiastic than Sheehan about this search for a writer's scene. The countryside was not safe anywhere. The trip required going in by helicopter, and, by now, the North Vietnamese had heat-seeking missiles that could bring down a chopper at 7,000 feet. The pilots had developed an unusual landing technique: "They would hover at 9,000 feet until you told them where to come down, and then they would drop like a rock."

The first chopper pilot missed, and Sheehan had to be hauled back out for the night. The next landed him in a minefield, the skids setting off a trip flare as it left. Sheehan froze in fear, a friendly, curious Montagnard soldier watching from the edge of the field. Perhaps no group had suffered more in the war than the Montagnards, a primitive, unassimilated and fiercely proud mountain people who had still worn loincloths and fought with bow and arrow when Sheehan first arrived in Vietnam. Now these tribesmen faced not the loss of a war, but extinction. Cautiously, the soldier walked through the field to the strange American, then led him back out, retracing his footsteps.

Sheehan stood in awe at the crash site, a lonely copse of trees surrounded by cut-and-slash desolation. What irony had caused Vann, who had taken so many reckless chances, to accidentally strike this lonely group of trees; what irony, indeed, had caused the trees to remain amid all the desolation?

Then he saw the strange wood markers and primitive carvings amid the sheltering trees. John Paul Vann had come down in a Montagnard cemetery, dying among the dead of those he had come to save. "It was spooky, very spooky. I don't believe in the supernatural, but it was almost that -- almost supernatural."

Neil Sheehan went home to Klingle Street, certain he had a remarkable book. A little more digging, of course. A couple of years and he would have this out of his system. N JANUARY OF 1974 HE HAD HIS first major setback. The subject of an earlier book had sued for libel and now the suit had grown messy. Delay the Vann book, his publisher's lawyers instructed, and help prepare a defense for the lawsuit. Sheehan, disheartened but with his Irish up, dissected his book page by page, writing a defense that was longer than the original manuscript. It took 10 arduous months.

In November, dispirited and exhausted but with the legal chore finished, he decided to take a few days off at the family cabin in West Virginia. It was early evening and a first wet snow was falling when headlights emerged directly in front of him. In the collision, he suffered 11 fractures. Bones were broken in both arms, his right knee and his chest. He was hospitalized for two months. It was four months before he could type even belaboredly, six months before he could drive a car, a year before the physical therapy was down to less than three hours a day and still longer before the exhaustion left him.

Midway through his recovery, Saigon fell and he ached to go for the final act. But his body wouldn't let him, and then his war was gone for good.

As his arms healed, he tried to start writing, perhaps too soon. It wouldn't come. He thought about quitting: "I mean, I was really clobbered, physically and mentally." His friends urged him on. His old Saigon buddy, David Halberstam, doubly famous because of his own epic Vietnam-era book, The Best and the Brightest, pushed him. " 'Don't let it stop you,' David said, 'Go on. Finish your book.' And he was right. Obviously. Nobody realized it would take so many years. I didn't realize it would take so many years. If I had, I never would have started it. Obviously."

So Sheehan went on. In 1977 he earned less than $1,000. He found more fellowships. Susan was becoming critically acclaimed, a beautifully craftsmanlike writer for The New Yorker. But Susan was as microscopic in her research and almost as painfully slow as Neil. Money became a terrible problem. The Sheehans were not food-stamp poor; they were never food-stamp poor. They just never knew where their next dollar was coming from.

By 1979, seven years into the ordeal, John Paul Vann was still a remarkable story that wouldn't fit neatly into a book, and Neil Sheehan was flat broke. In a grocery store he bumped into Peter Braestrup, an ex-Marine, a former Vietnam correspondent and now an executive at the Woodrow Wilson International Center for Scholars.

Sheehan was ready to quit. Braestrup offered what he was afraid to ask for: yet another fellowship, his fifth. It provided $30,000 and an office, carrying him through 1980.

Braestrup joked about it later. "I didn't get any work done that year," he said. "Neil talked about Vietnam all day long every day."

For Sheehan, however, it was a turning point. John Paul Vann began to jell during the nights at Klingle Street. The next year Random House more than quadrupled his advance to $200,000, removing some of the money pressure. He figured he had a couple of years to go. He always figured he had a couple of years to go. He had eight. Y THIS TIME MARIA WAS 13 years old, Catherine 11. Maria had vague memories of life before The Book, Catherine none at all. In the Hollywood version the kids would have been pretty screwed up. They were not. They were perky girls, good students, quick-witted, free of all but the usual kid rebelliousness. continued on page 51

"Life seemed normal to me, the hours, the schedule, Mom away on her work a lot, Dad upstairs on the book," Maria said. "You had your usual things you wouldn't understand as a kid. Daddy would come downstairs and say Book 3 is finished, and we'd celebrate. Then the next day he'd be back at work again. When it got to Book 7, I began to wonder how many books are there in a book. But to a kid, whatever is is normal."

When Catherine heard that one she squealed in delight. "Normal?!" she exclaimed. "One sentence a day is not normal under any circumstances!" Then her eyes bore in sharply to make sure you understood. That was a joke. She loves her Dad. N 1983 SUSAN SHEEHAN WON A Pulitzer Prize for her book Is There No Place on Earth for Me? It was her fourth book, the third since Neil had begun the ordeal, and she was at work on a fifth. Washington is a catty town, and it buzzed for a while about the irony: Susan wins the Pulitzer, and Neil seems to be no place on Earth. But Neil didn't care. He truly didn't care about his Pulitzer rebuffs, and he was immensely proud of Susan. He had his own little quarry, his chisel and a couple of years to go.

"It's hard to get a handle on Neil," Susan said. "I could talk about 30 people I know, or 50 people, and explain them more easily. He's different. He's really different. But he does not feel envy. He was raised very poor, and I used to wonder what it was like for him at Harvard with classmates like the Aga Khan and Jay Rockefeller. Once he took me back to Holyoke and, instead of showing me the very unscenic sights of a paper-mill town, he pointed out a highway cloverleaf and said, 'See, I worked on that.' So I asked him what it felt like, working on that cloverleaf while his friends were off at the Vineyard, or in Europe, or wherever they went in the summers, and he said, 'Whitney was Whitney Ellsworth, and I was Neil Sheehan.' "

"Dad was never going to be a sprinter," Maria said. "It took me a while to figure that out. Once, when I was in the second or third grade, I was entered in the 50-yard dash at St. Patrick's Day School. Dad took me aside and said, very seriously, 'Now don't look at the kids on your right and left.' And I thought, 'Oh, boy, more of Dad's advice.' But I didn't, and there was this girl right on my ear, but I won. Dad's that way. He doesn't look right or left, just straight ahead."

As time wore on, his old friends worried about him. Charley Mohr, a Times colleague whose friendship went back to the early Saigon days, knew that Sheehan liked to go bird-hunting. For years Mohr called, and each time Sheehan said, No thanks, Charley, sorry, it's a workday.

Others had unexpected contact. Keyes Beech, a veteran correspondent from the Chicago Daily News, recalled: "I'd get these calls in the middle of the night, I don't know what time, 3 a.m., I guess, because I was sound asleep, and this voice would say, 'Keyes, do you remember what happened at such-and-such a place in Vietnam on such-a-such a day?' I'd grunt something, which I'm sure started with 'Jesus.' Then he'd say thanks and hang up. Never did say who it was. Then a couple of years would pass, and I'd get another call."

The kids could joke about it at times, about their eccentric father with his militarily regimented ways, chiseling out his sentence a day. His schedule may have been bizarre, but it was precise -- six nights a week, with Sundays off for walks in the countryside, for 16 years.

"Have you ever watched him eat his breakfast?" Maria asked. "He fills the bran up to a certain line on the bowl. Then he fills the milk up to the next line. He never varies. Not long ago he was talking about taking the bowl with him on a trip, and the family just rebelled. I mean rebelled."

But they worried about him, too.

"The tension in him was never-ending," Catherine said, "and as time went on, he seemed to get more and more tired. He would come downstairs and he would look just awful, and it worried me. It really worried me."

Maria would sneak into his den while he was asleep and leave notes on his desk calendar: "Keep huffle-humping, Daddy." After a while she began seeing her father's own notes on the calendar: "I've got to do more huffle-humping."

Susan took to clipping little inspirational sayings out of the newspaper -- "Put all your eggs in one basket and keep your eyes on that basket" -- and warding off the people who would ask Neil if he didn't worry that time was passing, that Vietnam was too long ago now and, well, you know, that he was losing all these years, the best years of his life. "People didn't mean badly," she said. "But they're not good at dealing with cancer."

Sixteen years . . .

It was like a cancer, really, and when Sheehan finally describes the nightly battles he fought with the hobgoblins of his own soul, it comes out in a gush.

"I got this overwhelming anxiety, the anxiety would just be enormous," and his arms outstretch as if it were beyond breadth, "and it went on for years and years and I had to find a way to control it. It would exhaust me, and I'd be absolutely exhausted trying to figure out how in the hell am I going to get to the top of this mountain?

"I would get so overwrought I would get this god-awful insomnia, and you have to sleep to work, and I had to work. Sometimes I'd make a breakthrough walking around the neighborhood. I'd fight a problem all night long, be terrified with anxiety, and ba-boom, I'd get it. I'd come back and scratch it down on a pad, and then I could sleep. But when you can't sleep, you get frantic. My stomach gave out on me, just terrible stomach pains, and I was trying to live on chicken soup and rice. I lost 15 pounds and was doubled up in pain. And I went to the doctor and had all the tests, and he said, 'Neil, there is nothing wrong with your stomach. It is just nerves. It is stress. You can drink coffee. You don't have to survive on chicken soup. You have to learn to control the stress. Take hot baths and long walks.'

"I get tics in my eye. It's like in combat. You stay in combat for a week and ou start getting twitches in your face and pains in your side. There was this battle in Danang, a little civil war really, and after a week of it I was gagging every morning for about 15 minutes. It's a helluva lot of tension when you are sitting there trying to write a story in a building with a tin roof and people are shooting 81-millimeter mortars at you. It was like that, and it went on year after year.

"The only way to control it is to get up and YOU MARCH. It may be raining, it may be snowing, the sun may be shining, but you get up and YOU MARCH. The Army taught me some of that. Get up! The 10-minute break is over! Get up! March! And so I slapped myself in the face, threw water over my face and went on." IXTEEN YEARS . . .

Maria is 21 now, a graduate of Wellesley and working in New York, where she is a news intern at The Times. "Some kind of masochism, huh?" she says, grinning. "Don't ask. It would take years of psychotherapy to figure out the whys." She wears a T-shirt that says: "Daddy's Book Is Done."

Catherine has a T-shirt, too. She is 19, a sophomore at Wellesley and works as the office manager in Sen. Edward M. Kennedy's reelection headquarters in Boston. She still has hopes for the family vacation that never happened. "Maybe next summer," she muses. "Now that really says something about the optimism of the human race, doesn't it?"

Homer Bigart is 81 years old now, retired and living in a farmhouse in West Nottingham, N.H. He is an insomniac and read the New Yorker excerpts, sometimes till dawn's first light. "I could feel the kid's agony between the lines," he says. "But you tell him he did okay. The kid did okay."

Susan is working on, trying to stay out of Neil's limelight. Her favorite story is about the friend who introduced him recently: "I'd like you to meet Neil Sheehan, the about-to-be-famous-again author." When it was finally over, she gave him a coffee cup. It has a message on the side, with the date and congratulations for finishing his book: "Your huffle-humping paid off. Well done. Hurrah!"

At the house on Klingle Street, it is late afternoon, and Sheehan takes a sip from the cup. "I've got another cup from Susan, you know," he says. "It's dated 1983. That shows how many illusions there were about when this thing would be over." o it's really over now? All out of the system? The last prisoner has finally come home?

"Yeah," the voice comes back uncertainly. "I think this was my destiny. I was drawn to the war as a young man. It was the major experience of my time, and I never got away from it. Yeah, I'm rid of it now . . . but it's a strange feeling to be without it, a very strange feeling."

The talk turns to the future, but Sheehan isn't very good at talking about that, he has spent so many years suppressing thoughts of it, and the late-afternoon conversation winds down so he can eat breakfast, filling the bran up to a certain line on the bowl, filling the milk up to the next line.

A few nights later, Sheehan calls. "You remember we were talking about the future?" he says. "I've been thinking about it. What I'd really like to do is go back to Vietnam -- for an extended period so I can get a sense of it, you know, and do some writing about it. You know."

And put an ending on it. You know. And you also know that behind Sheehan, over at the house on Klingle Street, the serene, all-seeing Buddha knows. ::

William Prochnau is a 1988 Alicia Patterson Fellow and is writing a book on Vietnam war correspondents.