The marine is immaculate. He stands at attention inside the embassy, with his polished sidearm glinting at his hip. He looks like a mannequin, a perfect toy soldier. Nothing is out of place. The high and tight buzz cut, the dress blues, the blood stripe, the white-white gloves, the green fourragre tassel, the white cap with its chin strap so firmly cinched it cuts a groove in his skin.

The little boy stares up at the Marine as though he's seen a ghost. "What's that?" he asks, and he points at the radiant creature. His dad shushes him, his mom reminds him it's not nice to point. His older sister and younger brother are there too. They are an American family from West Virginia, just off the plane. Groggy and jet-lagged, they're waiting to get their official identification badges. The boy is five years old, and he has come to live at the American embassy in Tehran, where his dad, a navy Seabee, has been posted as a security engineer.

The year is 1977. The Shah is still in power, but the country is sliding fast into revolution. The family takes an apartment right on the grounds of the embassy, not far from where the Marines stay. Every morning the little boy sees them coming and going. He watches them with his dark brown eyes. He studies their strange movements, asks them endless questions. They pat him on the head and give him presents. They call him by his name – Shane.

One day the boy is swimming in the embassy pool with his parents. A couple of Marines march briskly by, off to somewhere important. They cut familiar looks at him and smile. The boy's fascination with the Marines has yet to wear off. Something about them grabs him – the discipline in their posture, their splendid formality, their ready competence, their otherworldly air.

"Look," the boy says to his parents, and points. "That's what I want to be." He says it with a resolve they'll never forget, a resolve they're not altogether comfortable with.In the predawn darkness on Friday, March 21, 2003, the sandy plain of southern Iraq still holds the previous day's heat. Marine Second Lieutenant Therrel Shane Childers stares at the flickering outlines of a vast oil pumping station, listening to the murmur on his intersquad radio. He rides standing in his "track," a 28-ton amphibious assault vehicle, pointing out developments on the horizon, his Kevlar helmet bobbing high above the hatch in the desert air. Perched up there Childers presents a clear silhouette for any snipers who might be waiting in the darkness. It's a posture that worries some of his platoonmates, who at times think their lieutenant carries himself with a confidence that borders on the reckless – "like he thought he was Rommel or something," as one of his men will later put it.

Childers roars across the Rumaila oil fields in a large convoy – some 200 men riding in several dozen tracks, Humvees, and tanks. His lip bulges with Copenhagen as he alternately fidgets with a map and squints at the landscape. The country, what little Childers can see of it in the darkness, is flat and featureless and marked only by the occasional piece of derelict petroleum equipment half-swallowed by the sand. Up ahead trench oil fires burn in large arcs around the pumping station complex, laying down a mantle of noxious smoke that has rendered his night-vision equipment useless.

Childers is a rangy, meticulous man quivering with energy. He has a triathlete's build and smoldering eyes the color of bittersweet chocolate. He speaks in a steady voice that, in accent, is a blend of West Virginia, Mississippi, California, Puerto Rico, Wyoming, the Carolinas, and all the other places he's lived in his 30 years – which is to say there's no discernible accent, only the resolutely American voice of the Corps. Childers's face is lit by periodic explosions, flares, and antiaircraft tracers. He seems happy to be where he has always wanted to be, leading a platoon of United States Marines into combat in the opening hours of a major ground war.

Childers clutches his M16 rifle. He's wearing a Finnish-made Suunto digital watch, a Kevlar flak jacket with slide-in ceramic plates, and a load-bearing vest packed with ammunition. A Mag flashlight on a lanyard is slung around his neck. He carries a compass, a GPS device, two canteens, three radios, two smoke grenades, and two M67 fragmentation grenades. On top of it all he's sheathed in a charcoal-lined NBC (nuclear/biological/chemical) suit that makes him sweat profusely. His gas mask dangles in its canvas creel at his side.

Childers's company – Alpha Company of the Fifth Marines (known as the "1/5") – has been given one of the first clear missions of the ground war. Their assignment is to secure an important facility in the vast Rumaila oil fields, a complex marked on the map simply as "Pumping Station No. 2." The station is enormous, 1,500 meters square, an industrial labyrinth designed to pump and pipe crude from a nearby gas-oil separation plant east toward the port ofUmm Qasr. According to the recon reports an entire Iraqi brigade of more than 1,000 men has dug itself in at the compound and is poised to either fight or blow the place up.

Childers takes a long pull from his CamelBak hydration pack. As the commander of Alpha Company's 2nd Platoon he is in charge of the fate and welfare of 42 men, most of them kids 18, 19, 20 years old. At Camp Pendleton, their base on the Southern California coast, he's had the better part of a year to mold this particular group of grunts. Fifteen of them are squeezed inside his track right now, and Childers can sense that they're anxious about the coming battle. He gives them a pep talk, reminding them that they've spent weeks training for their objective. During the long stay in Kuwait he had his men poring over satellite imagery of the pumping station and studying photographs provided by Predator drones. They constructed a scale model of the facility and rehearsed seizing the compound. "We're ready," he wrote in a letter home shortly before their departure. "Every day we just get harder and tighter, more disciplined."

Now Childers's track idles with the other vehicles in the Alpha Company convoy, which is aimed at the pumping station in an enormous diamond formation. "You're good to go!" Childers shouts over the deafening rumble of the diesel engines. "You're the best fuckin' devil dogs in the 1/5 – I'm proud of you!" He listens intently to his radio headset and waits for the signal to attack.

At about 3 a.m. Marine artillerymen unleash a barrage of mortars and rockets on the pumping station, a furious assault that lasts some 20 minutes. In an effort not to destroy the plant they're trying to secure, they train their sights only on outlying buildings where recon indicates that the largest numbers of Iraqi soldiers are holed up.

A few minutes later the signal comes. Metal ramps drop from the backs of the tracks, and Childers and his platoon storm down on foot, fanning out across the vast complex."He was living for that day," says Sergeant Bradley Nerad. "Man, he was in it for this."

Nerad sits in a debriefing room at Camp Pendleton, the immense military preserve pinned between the sprawls of Los Angeles and San Diego. A burly hoss of a man from Wisconsin, Nerad is the staff sergeant for Alpha Company's 2nd Platoon – Childers's unit. Like all the other Fifth Marines, he has just returned from Iraq. Their belongings from the war are parked outside, crammed into green metal containers that have yet to be sorted. Members of the 5th Battalion march in tidy columns nearby, preparing for a change-of-command ceremony. Many of them still wear bandages and dressings from various gunfights in Iraq.

It's late June and Camp Pendleton, home of the "Fighting Fifth," the most decorated regiment in Marine history (its unofficial motto is "Make Peace or Die"), stirs with the triumphant sounds of long-absent war machines. Bright banners are draped over the gates, and the returning Marines have been greeted as heroes at the conclusion of a successful mission.

But the war isn't over, and everyone here knows it. American soldiers are still dying in Iraq at a steady snare drum's beat – dying in checkpoint ambushes, in sniper shootings, in suicide bombings, in drive-by incidents too numerous and too messily ordinary to lodge in the public's memory as anything more than a blur of low-grade despair.

Nerad doesn't know what to make of the war now. Mostly he just looks relieved to be home. He's worn out, sick of sand, and in dire need of alcohol. Tomorrow he goes on leave, and he'll do what he can to forget the past four months.

Right now Nerad wants to talk about his buddy Childers. As the highest ranking noncommissioned officer in the platoon, Sergeant Nerad often butted heads with the lieutenant. "He was zealous. I'd say overzealous," Nerad says, shaking his head and smiling. "Sometimes he wanted to work the platoon to death." But it's obvious Nerad loved Childers, and worried about him, like a brother. Childers was lonely, he says, in the way that the most hardcore Marines are lonely. Such was his devotion to the Corps – to the ascetic purity of the jarhead existence, to the hard life of fitness, to all the Marine protocols and nomenclature and lore – that there wasn't room for much else.

He would rise before dawn every morning and go running before breakfast. He'd swim laps in one of Pendleton's Olympic pools, or take his $2,000 road bike on long rides around the base. He was keenly interested in the nuances of ballistics and was constantly trying to perfect his aim or work out the bugs in the sights of his various weapons. "He wouldn't socialize much," Nerad says. "He wouldn't go out drinking with the others and come back red-eyed. He'd be out driving around in his red Ranger pickup, buying stuff for his platoon at Home Depot – batteries, lumber, stupid stuff he thought they needed for their training. Then he'd just go home, to his apartment in San Clemente, get a bottle of Johnnie Walker Black, and stay up all night, sipping Scotch alone." He'd dig into one of the hundreds of technical military books on his shelf, titles like The Art of the Rifle, Maneuver Warfare, Stormtroop Tactics. As the night wore on, Nerad says, he'd "get to dreaming up shit to do with his platoon. He'd go online, looking stuff up. Sometimes he'd call and wake me up at, like, three in the morning, just to talk about some exercise he had in mind. He'd want to talk for hours."

Childers enlisted in the Marines when he was 17, a headstrong high school senior from Saucier, Mississippi, a small Gulf Coast town near the Little Biloxi River. He completed his basic training at Parris Island, South Carolina, just in time to be shipped out for the first Persian Gulf war. After the war (the duration of which he spent on a navy warship in the Gulf) he volunteered to stay on to help ship back supplies, then floated the Mediterranean and the Pacific on extended Marine cruises. He spent the next several years at North Carolina's Camp Lejeune, taking specialized courses such as jump school and training for night navigation. Then, like the proud Marines who so transfixed him as a kid in Tehran, he earned a diplomatic post as a guard at the American consulate in Geneva. He escorted foreign VIPs around town, traveled to Paris for a high-level diplomatic conference, and took an avid interest in outdoor sports, spending much of his free time climbing, mountain biking, and whitewater rafting in the Alps. A year later he accepted a similar assignment at the embassy in Kenya, where he climbed Mount Kenya, went on Serengeti safaris, and pursued an intense love affair with a beautiful young Israeli woman named Adi. He considered converting to Judaism, in part to please her family and in part because the demands of the faith appealed to his sense of rigor. But ultimately the relationship fizzled.

At the advanced age of 25 Childers, then a sergeant, decided he wanted to become an officer. To do that, however, he knew he had to graduate from college, something no one in his immediate family had ever done. In 1998 he qualified for a special program that landed him at the Citadel, South Carolina's venerable military academy. He consumed the experience whole, majoring in French and landing on the dean's list, competing in numerous school triathlons and exploring parts of the Appalachian Trail on breaks and long weekends.

Then he resumed life in the Marines on an entirely different career track. Childers had become what the Marines call a "mustang," a special breed within the ranks. Mustangs are officers who earn their commissions relatively late in their careers and who, as a result of their grunt pedigree, often still act and perceive situations like noncoms. Enlisted men say you can't get anything past a mustang, because he's already seen everything and knows all the tricks. Having gotten most of their carousing out of their systems, mustangs tend to be more serious than younger officers. It's often said that mustangs have a total perspective that gives them a special confidence on the battlefield.

Certainly all this was true of Childers. But he could also be moody, Nerad says, and he had his moments of anxiety. Nerad remembers one such moment just days before the war. They were bivouacked in a huge tent city in Kuwait that the Marine planners christened, with characteristic poetry, Living Support Area Number Five. Everyone was bored, frustrated by the false warnings, the seemingly endless ramp-ups and rev-downs. Childers and Nerad were sitting around talking about what the war would be like, wondering when they'd finally be crossing the LOD, the line of departure. Maybe his nerves were getting the better of him, but at one point Childers stared off into the distance and said, with an unfamiliar severity in his voice, "I probably won't come back."

Nerad looked at him funny. "Hey, c'mon."

"I don't know, man," Childers said. "I just don't think I'm coming home."

Nerad tried to reassure him. "You bet you are," he said. "The Marines need you – you know too much."

Whatever it was, Childers couldn't shake the feeling. It lingered in the air for an uncomfortable moment. Then he turned away and fixed his eyes on the desert.Childers and his platoon comb the burning outskirts of Pumping Station No. 2, looking for signs of life. The Marines wield grenade launchers, SAWs, and M16s, and sweep flashlights over every recess of the compound. Aside from the steady drone of pumps, turbines, and generators, the site is eerily quiet. All the lights have been switched off. Throughout the complex are freshly dug foxholes, but the "brigade" of Iraqi troops appears to have vanished. The grounds are littered with American propaganda leaflets air-dropped days before, urging prompt surrender. Many of the buildings look as though they've only recently been vacated. Burning candles sag in lumps of glistening wax, and plates of half-eaten dinners sit on tables. Bedding and prayer mats are tossed about in corners.

Childers is having trouble getting a fix on how, or even if, the Iraqis have been planning to defend the place. It appears to him that they've been taken completely by surprise. As he and his men move deeper into the compound they can see that the artillery barrage prior to their attack took a toll. Perhaps a dozen corpses are scattered about, and a number of Iraqis lie moaning in pathways and by roadside ditches, clutching shrapnel wounds. On his headset Childers calls in medical corpsmen to treat the wounded.

A few Iraqi soldiers begin to emerge from crude underground bunkers. They offer themselves up in ones and twos, waving grimy white rags, their hands up, trembling in fear. Some wear green Iraqi army uniforms; others wear robes over their military garb, as though they're attempting to disguise themselves as noncombatants. Many seem to be civilians from nearby villages pressed into service. The Marines begin to round them up and bind them in zip-ties – handcuffs made of hard plastic.

Then, around dawn, Childers and his men spy an Iraqi soldier hopping onto a motorcycle and taking off across the desert. The Marines open up and eventually the Iraqi man is hit, hurled over the handlebars in a dust cloud. Still alive, he has a bullet hole in the back of his head and much of his lower face has been blown off. It is quite possibly the first shooting of the ground war.

As the sun climbs over the sand flats to the east, the assault on Pumping Station No. 2 is already winding down. Childers is ecstatic: In a few short hours his men have taken control of the facility. The first ground mission in Iraq is shaping up to be an unqualified success, part of a larger preemptive action throughout the region that military planners will later cite as one of the masterstrokes of the war. Any plans Saddam Hussein may have had to sabotage the oil fields have been averted. And there has not been a single American casualty.A gold star from the American Legion hangs by the front door of the Wyoming ranch house. The house is yellow, with a green shingle roof. It sits on a rolling, wind-beaten piece of land that's nubbed with sage. In the distance snow-dusted peaks jut up in every direction: the McCullough Peaks, the Absarokas, the Bighorns, the Pryors, the Beartooths.

Joe Childers greets me at the door. He's a strapping, generous-spirited man with a bulbous nose and spiky gray hair. He wears a Carhartt jean jacket and muddy cowboy boots. A tire gauge rests in the pocket of his denim shirt.

In 1990 Joe retired from his life of far-flung travel with the Seabees. He did two stints in Vietnam and then bounced around to nearly every corner of the world – Midway, Okinawa, Puerto Rico, Paris, Madrid, Jamaica, the Central African Republic. It was a fine career, affording a far better life for him and his family than continuing to work in the steel mills of his native West Virginia would have. Now he's a roustabout for a Wyoming oil company.

Mostly, though, he likes to lose himself in the work of this 125-acre ranch a few miles west of Powell, in the northwest corner of the state. Joe has owned this beautiful, ragged spread for more than 12 years, and it's his true love. Irrigating his fields with canal water diverted from the Shoshone River, he grows alfalfa and silage corn, and raises Black Angus, donkeys, mules, and Belgian draft horses. Old agricultural implements – harrows, rakes, sickles, grain drills, yokes, and horse-drawn plows – lie rusting everywhere.

Joe grabs two Bud Lights from the fridge in the barn. "Boy, Shane sure loved this place," he says. "Whenever he was on leave he'd come stay with us. He loved to go on long runs up there in those foothills. He'd just take off and be gone for hours. Last time he was here was around Christmas. We had a couple of feet of snow. He hitched up the Belgians to the sleigh and took off across the fields. You should have seen him up there, driving 'em."

By then Shane already knew that he would in all likelihood ship off for Kuwait. The Childerses have had a curious and long-standing relationship with the Middle East, as though their familial fate keeps circling back on itself. Living in Tehran at the end of the shah's reign, fixing locks and security cameras at the embassy and occasionally caring for the pleasure horses of the shah's rich friends, Joe witnessed firsthand the beginnings of America's toxic relationship with the Islamic world. All around him the country was unraveling. Nearly every day there were demonstrations or explosions or clouds of tear gas hanging over the city. Joe and his wife Judy, along with their three young children, were there for all of it. "Those were Shane's first memories of life," Joe says.

In late 1978, when all nonessential personnel were told to leave Iran, Judy and the children went home to West Virginia. In February 1979 Joe, along with most of the diplomatic staff, was briefly held hostage by Islamic fundamentalists who took over the embassy in a little-known precursor to the infamous hostage crisis that would shock Americans nine months later. "They stormed the gates and yanked down the American flag," Joe says. "They held us at gunpoint and marched us over to the ambassador's residence, and kept us there for a day." This anti-Americanism was still so new to Joe that he didn't recognize the full fervor behind it. He says, "I guess I wasn't as scared as I should have been."

We wander inside, where Judy is busy sorting boxes of sales orders that arrived this morning from Avon. She is a short, sturdy, direct woman from Idaho Mormon country, with a warm smile.

We sit down in the living room and Judy produces several family albums. She shows me a picture of Shane riding a horse in Spain, another one of him at a formal embassy function in Nairobi with Adi, stunning in her evening gown. "Here's one when he was just a little bud," Joe says. It was taken in Puerto Rico, where Joe worked at Roosevelt Roads Naval Base. Shane is holding a palm frond that's three times his size. He looks at the camera with those brown eyes, eyes that seem to look through you and on toward some distant beckoning future. The image is slightly blurred, as though Shane is moving too fast for the camera.

In high school Shane held himself to a demanding but unpredictable standard of perfection. He argued a lot, especially with his mom, and could be insufferable when advancing his notions. He had a fierce intolerance for bullies of any kind and did not hesitate to confront them. He played catcher in Little League. He hunted squirrels, fished for crappie and bream. By his sophomore year he was already molding himself to be a Marine, gulping down raw eggs, doing hundreds of sit-ups, running untold miles, and reading all the literature on the Corps he could find. He signed up for an early-entry program and never looked back.

Judy serves up three enormous steaks, extra-rare, from their private herd. "You know," Joe says, carving into his meat, "I've been around animals all my life. It's almost always true that if one in the litter's going to die, it's going to be the best one. Pigs, chickens, horses, cows – that best one, you watch him, he's gonna up and die on you."The desert sun is blinding but not yet brutally hot. By 7:30 a.m. the trench fires around the pumping station and gas-oil separation plant are slowly extinguishing themselves. The men of Alpha Company, raccoon-eyed from having worked all night, buzz with excitement over their successful action. What started as an assault has become defensive in nature: The Marines are now policing the area for any remaining threats before turning over the entire facility to a unit of British soldiers and petroleum engineers.

Then, a little after 8:00, an explosion shudders the complex: Corporal Brenton Groce, from Alpha Company's weapons platoon, is searching one of the many outbuildings when he triggers a land mine. The blast blows Groce's boot off and mangles his legs. He has two broken ankles, a fractured tibia and fibula, and numerous shrapnel wounds. Medical corpsmen stabilize him and then radio for a CH-46 helicopter to medevac him to Kuwait.

With Groce's injury everyone's nerves are suddenly on edge. They've been fearing land mines all along, but the incident has injected a measure of reality into what had begun to seem a war without repercussions. Now the Marines step gingerly about the compound, trying to finish mopping up.

Around 8:30 the men of Childers's platoon make one last sweep of the area but fail to find any more prisoners. The complex appears to be flushed clean. Childers is satisfied that his platoon's assignment has been fulfilled, so he decides to bring his men together and conduct a debriefing. He yells to his scattered men to collapse back to the vehicles. The tracks are parked together along the side of the road to the east of the pumping station beneath a clump of scrubby desert trees. About a hundred yards away a severed oil pipeline running parallel to the road exhales a continuous breath of fire and smoke.

"Collapse back to the tracks!" Childers shouts again, this time giving the command to his squad leaders over his headset. "Roger that!" he hears back. The 40 men of his platoon abandon their various searches and funnel back to await Childers's next instructions.

Suddenly a tan Toyota pickup truck squeals around a concrete barricade and barrels down the pumping station road toward the tracks. Most of the Marines are turned away from the road, their backs to the truck, and it takes them a moment to pick up on the sound. Childers hears the revving engine and instinctively walks out onto the shoulder of the road to investigate. Most of the other Marines are partially hidden by a berm nearby. Childers crouches down and squints at the truck. It looks harmless, but for some reason it keeps on coming. Someone requests permission to open fire, but Childers gives no order.

The truck continues to accelerate – 40, 50, 60 miles per hour. Now Childers knows something is wrong. He stands up and switches his M16 from safety to fire. The machine-gunners up in the tracks watch with growing concern, but the truck is already so close that there's no time to swivel their big 50-caliber machine guns into position.

The truck races at 70 miles per hour. Childers can see that it's packed with six or seven people, some of them lying low in the bed.

Childers raises his M16 to fire. He hears the Marines behind him fire off a few rounds, but the truck keeps coming. Now the Toyota is right on him, no more than eight feet away. One of the squad leaders, Corporal Jesse Odom, is crouching next to him. For a split second Odom locks eyes on the Iraqi driver. There is fear and desperation in the driver's face, and anger. The Toyota swerves toward them. Odom sees the barrel of a weapon peek from the driver's side window, and as the truck passes by he sees muzzle flashes and hears a stitch of automatic fire. The desert dust kicks up all around him.Corporal Jesse Odom is a bright, young, jug-eared fellow with cropped strawberry-blond hair. He's from Easley, South Carolina, and speaks in a firm, earnest Southern voice. He stands at a chalk board at Camp Pendleton, drawing a diagram of Pumping Station No. 2, marking it with vectors and crosshatchings, trying to explain how a simple situation could slide so thoroughly out of control in a few seconds.

As Odom stares at the diagram he wonders why he's alive – why the bullets spared his life. He's in his mid-20s and still having trouble grasping the caprices of the war from which he has just returned –unharmed, but not untouched.

"That truck, shit – I still don't know where it came from," he says. "Up till that point I guess you could say we were kind of cocky. Damn, it pissed us off, shocked us. It made us keep our alert up – really, for the rest of the war."

Odom, like many of the Marines, has come to view that first day of battle as an encapsulization of the whole war – the speed and confidence with which they seized their objective, the almost eerie lack of initial opposition, the feared chemical counterattack that never came. Then, as they began to encounter Iraqis face to face, Childers's platoon had to deal with the complicating wrinkle that the enemy in this conflict was not to be regarded as an enemy but as a potential friend, a repressed victim of a bad regime. And finally, later that morning, the Marines found themselves entering an even riskier and more open-ended phase, the paranoid policework of occupation.

The incident at Pumping Station No. 2, Odom believes, was a kind of ambush in reverse: The Iraqis in the Toyota, attempting to flee the pumping station complex, were startled to find the Marines dug in by the road, and reflexively struck out with a spray of AK-47 fire as they tried to speed past. Childers, like any good platoon commander, was in the center of things, at the point of maximum danger, looking out for his men.When Childers absorbs the bullet, his body doesn't immediately register the impact. He has a puzzled expression and he exhales in a groan. With his rifle still in his hands he drops to his knees. Then he falls slightly forward, his helmet tapping the ground. He rolls sideways and curls into the fetal position.

Not entirely sure what's happened, Odom crouches next to his lieutenant. All he can see is that Childers is having trouble catching his breath. For a second he entertains the slim hope that maybe Childers has only had the wind knocked out of him. But then Odom peers into his lieutenant's eyes. They're staring off into space. His expression is vacant, the face hardly recognizable. Childers struggles to say something. "I'm hit," is all he can moan. "In the gut."

Odom spots a small round hole in Childers's uniform, on his right side, just below the bottom of his Kevlar vest. The puncture is about the size of a large pea. Curiously, he can see almost no blood.

Someone cries for a medic, "Corpsman up!"

The Toyota truck has sailed by and is now some 50 yards down the road, racing toward the east. The men "light up" on it. Marines like to say that if they take an enemy round, they reply with a hundred rounds. In a murderous staccato a dozen or more weapons drill the vehicle with bullets. Yet the truck keeps on accelerating.

Odom can see that Childers has stopped breathing. He decides not to wait for the corpsman to get there and bends down to give mouth-to-mouth resuscitation. There is a trail of tobacco juice on Childers' lips, but Odom hardly notices. He breathes into his lieutenant three or four times.

Childers's eyes blink open. "Can't believe it," he mutters. "Can't believe I got shot."

The Marines are still blasting away at the Toyota. Finally, a hundred yards down the road, the truck veers sharply to the side and comes to a stop close to the billowing break in the oil line. One of the occupants dangles a white shirt out the window and waves it. A smaller party of Marines runs down the road and approaches the vehicle.

Odom is still crouching next to Childers when Jeffrey Calzado, one of the navy medical corpsmen attached to 2nd Platoon, arrives. Calzado hunkers with Odom and inspects the lieutenant. He can see immediately that Childers is in severe shock. Tears well in Childers's eyes. His pant leg is stained with urine. His breathing is erratic, his skin cold. The hole in his abdomen is immaculate, seeping only a tiny amount of blood. Calzado knows that a bloodless bullet wound is not a good sign, that the real bleeding is internal.

In a barely audible voice, Childers says, "It hurts."

They decide to move Childers somewhere safer. Odom hoists him over his shoulder and hauls him back to the cluster of vehicles parked beneath the trees. He lays him down on the metal ramp of one of the tracks.

Other corpsmen stream over to help. They cut away Childers's clothes and equipment with shears, leaving him dressed only in shorts and the blouse of his NBC suit. Noah Glanville gives him a shot of morphine. Calzado props up his legs and checks his vitals. Another medic, Shelton Tapley, administers an IV. When they examine the wound more closely the corpsmen discover that it's actually two wounds: The bullet entered the abdomen just to the right of his navel, went through his left kidney, and cleanly exited his back.

The bullet – most likely a .308 caliber round from an AK-47 – hit a few millimeters below the ceramic plates of Childers's Kevlar vest, possibly striking at the instant when he was raising his weapon to fire, when the vest was momentarily hiked up higher than usual. The bullet angled in such a way that it hit a major artery. Now Childers is hemorrhaging massively. His blood pressure plummets, but still the wound shows only a trickle of red.

While the medics work on him the Marines hear the sound of another car approaching. A beat-up Land Cruiser stuffed with seven Iraqi soldiers charges down the same road, aiming right at them. Just as the last group had done, and the motorcyclist before them, they're attempting a fast break from the pumping station complex. But this time the machine-gunners in the tracks are ready for them. The oncoming truck, about 200 meters away, is clearly within their range. They swivel their big barrels and open up the 50-caliber machine guns. The enormous rounds shred the SUV like foil, and in a few seconds it has stopped, its body yawning with smoky holes. The Marines expect all seven of the Iraqis inside to be dead, so they're amazed to find three of them alive, their bodies maimed beyond recognition. One of the Iraqi soldiers sits with his intestines flung out over his lap.

With Childers down, Sergeant Nerad realizes that he is in charge of the platoon now. He inspects his lieutenant's M16 and notices that, although the trigger has been switched from safety to fire, the weapon hasn't been discharged. Nerad watches Childers struggling for his life. He urges him to stay strong and breathe, breathe, breathe.

The medics know now that the only hope of saving Childers is to chopper him immediately to a hospital in Kuwait. The helicopter that was supposed to medevac Corporal Groce, the land mine victim, still hasn't arrived, so the dispatcher puts in another request, this one issued with maximum urgency.

As the corpsmen continue to work on Childers, Odom stays at his side, stroking his face, talking to him gently. "You're the best platoon commander we could've ever had," he says.

Childers's pupils are dilated. His tongue hangs thick. He gives no reply.In the months leading up to the Iraq war Childers spoke to his folks about making a go of things as a small-time rancher like his dad – maybe even buying a spread in Wyoming. He loved horses and the challenges of working the land, and he felt more at home in the mountains of Wyoming than in any other place. He had begun to think seriously about other careers, too. He talked about becoming an FBI agent, or maybe returning to Africa as a military attachéat an embassy. In one of his last letters to his folks from his Marine campsite in Kuwait he wrote, "I wouldn't do things any other way, but I really do think of getting out after this tour. Have other things to worry about right now, though – Love you, Shane."

Yet the Marines were such an integral part of Childers's identity by then that even his closest friends wonder whether he could have actually made the leap to civilian life, whether it wouldn't have left too big a void. He was neither a churchgoer nor a flag-waver, exactly, nor did he have an allegiance to a particular political party or creed. Childers was a believer in the Corps, pure and simple, and in the fierce principles of professionalism and duty that the Corps had long instilled in him. He had certain self-sacrificial notions of what a Marine, a true Marine, should be.

In Iraq this allegiance to the Corps translated into a firm belief in the bedrock rightness of the mission at hand – to take out a particularly evil tyrant, to save the oil infrastructure that could help pay for the country's rebuilding, to unfurl the flag of democracy in a region of the world to which fate seemed to keep bringing him back.

One day in Kuwait, Odom recalls, "He told me, 'Make sure the Marines in your squad know why they're here, and that they're doing the right thing.' In camp he had read something in a newsmagazine that said, 'Nothing in Iraq is worth risking a single American life.' Well, that really pissed him off. He told me, 'There are things worth dying for. Make sure you tell your Marines that.'"

Lieutenant Childers's eyes roll back in his head. His breathing has become shallowand labored, and now he is completely unresponsive. The corpsmen ask Odom to open Childers's mouth and insert a special plastic implement designed to keep the air passages open. It doesn't work. Childers is down to eight respirations per minute. Tapley begins to administer CPR, but the lieutenant's breathing continues to slow down.

Meanwhile two Marines, Corporal Mike Cash and Corporal Brandon White, creep up on the bullet-pitted Toyota from which Childers was shot. Four Iraqi men, all of them badly mangled, emerge from the truck and raise their hands in surrender, crying, "No shoot, no shoot!" As a party of Marines lead them over to a makeshift holding area, Cash skulks up a little closer to the truck and realizes that at least one Iraqi is still trying to hold out. The man is hunched down low in the bed of the truck, but every few seconds he peaks over the rim. Cash yells at the man in Arabic, tells him to throw over his weapons and to raise his hands above his head. No response. Then he sprints toward the back of the vehicle and pumps eight rounds into the man, who slumps over, dead. In his lap is a loaded AK-47.

Cash and White then hasten back across the road to the holding area, where a heated debate has begun about whether the prisoners who shot Childers deserve medical attention. Some of the Marines' attitude, for now, is let them suffer. Cooler heads prevail, and the medics begin irrigating and dressing the Iraqis' wounds, setting up IVs, injecting morphine for pain. (According to a medical officer assigned to escort them to a hospital ship in the Gulf later in the day, every one of the four ended up surviving.)

Back by the tracks Tapley and Glanville have been working on Childers continuously for 15 minutes. He cannot breathe on his own. His pulse is faint and thready; then, his capacity to fight finally spent, it fades to nothing. Glanville shakes his head. A wound like this, there was nothing we could have done, he thinks as he packs away his equipment. Another medic closes Childers's eyelids and drapes the hood of his chemical suit over him like a shroud.

It's 9:00. Childers is laid out on the ramp of the ambulance track, a pale and strangely bloodless corpse dressed in shorts, his body marked by one perfect wound, left by one perfect bullet.

A few minutes later a CH-46 helicopter descends upon the site in biting swirls of dust. The Marines rush Corporal Groce inside and then carefully place Lieutenant Childers's body next to him. Slowly the helicopter climbs over the smoldering grid of Pumping Station No. 2. and heads for Kuwait.The marine is immaculate. nothing is out of place. The high and tight buzz cut, the dress blues, the blood stripe, the white-white gloves, the green fourragĀre tassel. His parents stand over his open coffin, crying, holding each other. The body has flown in a steady westward arc from Kuwait to Germany to the military mortuary in Delaware and finally here, to a funeral home in Powell, Wyoming, where on the night before the funeral a private viewing has been arranged for family and friends. The 12-day journey has taken its toll on the corpse. The face sags in the wrong places from dehydration, and looks darker and thinner than anyone remembers. A detail from Marine Casualty Assistance has come from Montana to make sure the remains are "presentable" and that everything is done according to the obsessive Marine protocols. They've seen to it that Childers's uniform is crowded with all the correct ribbons and medals – including his most recent commendation, a Purple Heart.

The Childerses stare and stare. They know it's their son lying before them, but they keep repeating his name aloud as though they're not absolutely sure, as though there's still some chance it's a mistake. Maybe he's still in Iraq, Judy thinks, policing the streets of Baghdad. Maybe he's coming home with the others in his platoon once the long mission is through. Or maybe he's still there on the battleground, in the desert oil fields he helped save, in the first hours of the first full day of the ground war.

The Marine protocol officer hands Judy a few of Shane's personal effects from Iraq. When she holds Shane's watch and ID tag the bottom finally drops out of her emotions and the tears stream down her face. Something about the specificity of the artifacts drives home the reality for Judy. The watch, in a sense, speaks of Shane's belief in precision and training, his obsession with equipment, and of a life of mastery that, despite every precaution, proved vulnerable. "He's really not coming back, is he?" Judy says.

And for just a little while longer, she and her husband hold each other and stare at their son and wail, "Shane. Shane. Shane."Lieutenant Shane Childers was declared the first combat death in the Iraq war, and was promoted, posthumously, to first lieutenant. At the time of this writing 324 American service members have died in Iraq.