"Watch out for Bose, he brings the rain," one of the E.R. nurses was telling me just before we got on the convoy to the forward base in Khadimiya. In this scorched climate, we could only hope for rain; the nurse meant that when Bose was around, they were always hit with mass casualties. Rain was bombings, convoy ambushes, nightmare firefights that brought in injured by the dozens. Bose works long hours when the rain comes, performing emergency surgery on the critically wounded. Because the patient load can spike so quickly, he spends his time between the forward base in Khadimiya and the combat support hospital, shuttling back and forth. But there still isn't enough of him to go around. When the staff of the emergency room talks about him, they always mention his intelligence. Bose, who has a great passion for medicine, gives you the impression of a determined physics student and seems detached at times, slightly dorky. But in five days, I never saw him hesitate over the name of a nerve, small bone or drug. It is not surprising. When Bose took his medical board examinations, he won the highest score in the country. To his colleagues, who have enormous respect for him, he is a star.

On Saturday, June 5, the date we were leaving for the forward base in Khadimiya, Lt. Chris Melendrez, the commander of Bose's medical platoon, arrived at the combat support hospital. Melendrez was there to pick up Bose and take him back to the base to take care of a soldier with a broken nose. When I met Melendrez, he was professional and focused on getting the convoy together. He called and made sure I was authorized to go back to the base. When I thanked him for taking care of all the details, he said, "Too easy, let's make it happen," his catchphrase. Melendrez is like Bose in some respects -- a young officer with immigrant parents -- but Melendrez is a committed soldier, a believer in the cause. Bose is an intellectual and an accidental soldier, and sometimes the two men might as well be from different planets.

Outside the hospital we piled into armored Humvees. On the ride up to Khadimiya, Bose and I rode in different Humvees, Bose in an armored one. There was very little conversation. Everyone was watching the road and the gunner was watching everything that moved on the street. When we were moving, Iraqi civilians stayed well away from the convoy, and when they didn't, the soldiers would give them the Iraqi hand signal that means "wait," an upraised palm with all the fingers brought together. They obeyed, knowing that driving anywhere near the American convoy was dangerous and invited bad luck. We arrived in Khadimiya safely.

After two months in Iraqi Baghdad, I wasn't prepared for the base. I expected the same bombed-out structures that served as makeshift shelters for the 1st Cav soldiers, but the base wasn't like that at all. It looked like a typical, pleasant if unusually racially integrated American suburb. If you could forget about the incoming mortars and the war all around it, Banzai Patrol Base was a utopian island. Saddam built his Information Ministry at a bend in the Tigris River, shaded by rows of palms, and it now serves as a place where American soldiers keep fit by running along the graceful roads winding through the campus. Heavy-metal music poured out of the gym next door to the Internet cafe. The soldiers watch movies and MTV, and make discount phone calls home at the local smoothie bar/Internet cafe. At a chapel near the Internet cafe, stacks of camouflage Bibles and plastic rosaries wait for the faithful. Later, when I was thinking about the base, and missing it, I realized that the soldiers who live here will go home to a country that is far more divided than this community. The noisy, tumultuous Iraq of teahouses, sun-beaten men selling propane from donkey carts and black-veiled women struggling down the streets full of brutal traffic had been rendered invisible.

We arrived at the aid station where Bose works as the frontline surgeon, and dropped him off. Lt. Melendrez then offered to take me on a driving tour of the base. Melendrez, who is in his mid-20s and looks like he wouldn't be out of place on a pro baseball team, has a lot going on. He would reveal his intelligence and sensitivity in the space of a few days, but these are qualities that edged past his adopted persona as a platoon commander. We drove toward a row of single-story buildings, where two Iraqi ICDC trainees were walking down the center of the road, blocking the way. They knew we were behind them, but they didn't move, keeping their backs toward the car, and this infuriated Melendrez. "See that? They do this kind of thing all the time," he said. When we finally passed the trainees, there was no acknowledgment, no greeting, which is uncommon for Iraqis. It was the first sign that something was wrong.

I asked Melendrez what he thought of the ICDC recruits. "I don't trust them farther than I can throw them," he said with some bitterness. The young officer then told me about the problems they had been having on the base, and said that one senior Iraqi officer, who had been trained by the Americans, had been the target of an arrest raid by the 1st Cav. Melendrez said that the Iraqi officer was accused of plotting against the Americans, but that he disappeared before they could find him. Soldiers on the Khadimiya base talked about the suspect loyalty of the Iraqi forces every day. It reached a peak whenever the base received accurate mortar fire from across the river.

Unlike Bose, who is even-tempered, Melendrez is outraged at the thought that the Americans are being betrayed on their own base. Just thinking about the Iraqi soldiers gets him going. He didn't like the ICDC, but they were part of the U.S. plan, so he had to work with them. Melendrez wasn't alone in his take on the Iraqi forces. All of the soldiers I spoke to felt the same way; their distrust of the ICDC verged on hatred.

Melendrez would have to travel with a few of the soldiers he distrusted the next morning on a medical assistance mission to a slum town called Badiat. Badiat was on the outskirts of Baghdad, a village where people farmed poultry and recycled debris. He planned the trip carefully and briefed his people in the evening in his office at the aid station. Melendrez chose the order of the vehicles, the time of departure, the route and who would be going. His men watched while he stood at the white board and went over the mission. The convoy would stop just outside Badiat and they would meet up with the local leader, then continue with him to a local school and set up the temporary clinic. Because there has to be at least one medical officer at the aid station, Dr. Bose elected to stay on the base, and his colleague Lt. Dean Stulz would go instead.

Bose, the brainy outsider, didn't seem excited about the Badiat mission. He skipped Melendrez's briefing and hung out in his room in his vast library of packaged food gifts from home. After noticing that the two men kept their distance, I began to think of Melendrez as the anti-Bose, a bearer of prejudices he couldn't beat, a man who was anything but detached. "You have to be hard with these people," he said to me, talking about the Iraqis. "That's what they understand." Bose would never fall prey to empty wisdom like Melendrez's comment about the Iraqis, even if he found them to be difficult patients. Bose often treated wounded fighters who came into the emergency room spitting and glaring at the doctors. "You could tell they didn't want to be there." It was the harshest comment he made about people who were working hard to kill and maim his friends. Melendrez, who has a short fuse, has much different feelings.

The next morning, guarded by three Bradley Fighting Vehicles, Melendrez's convoy made its careful way out to Badiat. We turned off the main road onto a dirt track, raising a comet's tail of dust. A stench came through the windows because we had entered a dump operated by freelance garbage men. Dunes of trash covered the open ground. On the other side of the rotting hills was Badiat. The first Iraqis we saw were middle-aged men straightening rebar on sawhorses. One older man took the bent rebar from a pile and worked the kinks out of it by hand, then put it in a few piles; he was dirty and the sweat ran down his face.

Melendrez got down out of the car, spoke to the rebar-straightener through an interpreter and asked for the local leader. "He's not here," the man said and glared at us. It probably wasn't true, but Melendrez was unfazed and decided to go on to the school. Half a mile down the road, the Bradleys set up a perimeter while Dean Stulz and his medics created a clinic. It took them about 20 minutes before they were ready to see patients. Since the soldiers couldn't tell the people of Badiat exactly when they were coming for fear of ambushes, citizens emerged from their houses, looking at the armored convoy with a mixture of apprehension and curiosity. A Humvee with loudspeakers drove around town advertising the clinic. At first they trickled in, but before long there were at least 150 people waiting for free medical care under the brutal sun.

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