The Iraqi informant is a new source, but his tip seems solid: The chief financier of a Mosul terrorist cell, a gas station owner, lives in the neighborhood. He is wealthy enough to afford two armed guards to accompany his son to Mosul University. Now, at 1:13 a.m., under a light drizzle, 25-year-old Lt. Mark Brogan and 13 men from his platoon crouch behind a wall, waiting for the signal to storm the house. The informant claims the financier and his son are inside. The two bodyguards, almost certainly armed, might be there as well. At last, 16 minutes later, the company commander in a Stryker armored vehicle down the block orders the soldiers to move. The men hustle to the gate in the wall surrounding the house next door. A ladder goes up and three soldiers clamber over. They open the gate from the inside and the rest of the men stream in, crowding next to a small sedan parked inside. Sgt. John Alvarez, the squad leader, puts his M-4 carbine to his shoulder and runs to the door, ready to smash it in. A man stands in the doorway waiting for him. "Down!" Alvarez shouts at the silhouette. "Get DOWN!" ___ Brogan and Alvarez's unit is Alpha Company of the 4th Squadron, 14th Cavalry Regiment - nicknamed the "Assassin Troop," and known for the giant skull painted on plywood hanging outside the bombed-out building they call home at Forward Operating Base Courage. They profess not to be frightened of the night's raid. They have executed more than they can count, and the operations usually go smoothly. They bash open doors, shout their targets awake and bind their hands with thick plastic restraints called zipcuffs. The captives are fitted with blacked out goggles and taken to base for questioning. But the raid this night will be a little more complicated. Earlier, at the base, Capt. Matt Eberhart, the 30-year-old company commander, instructed Brogan's team to go strong into the house thought to belong to the terror cell financier. Yet he has also told the team to then conduct a calmer "cordon and knock" at the house next door, where an old man acquainted with the source lives with his grandson. Neither is to be detained. Intelligence indicates the two houses are connected. "We're just making sure we're not going in there and shooting the grandfather in the head," Eberhart, of Lincoln, Nebraska, tells Brogan, of Kingsport, Tennessee. "If we do that we lose the source, because I get the sense there's a connection between him and the source." Brogan's platoon of just over 30 soldiers seems unfazed by their mission, though there's palpable anxiety as the men assemble beforehand to prepare. They smoke cigarettes and cigars, dip tobacco and laugh. It's cold and raining hard. As the platoon members joke, Sgt. Curlee Kelley, 28, of Stuttgart, Arkansas, tests them on what to do if things go wrong. What if they enter the house and a member of their team goes down? Eliminate the threat and then help the fallen man. What happens if the bodyguards start tossing grenades and firing AK-47s from the second story? Call for the Stryker out in the street to open fire with its heavy machine gun. They are reminded again not to damage the houses. They expect to find women and children in both. Make sure to separate the military-age males from the rest. A blue Opel sedan in the garage means the bodyguards are probably there. "What do we do with children, do we zipcuff them or is there an age limit?" a soldier asks. Kelley says his men must use their judgment - anyone able to fire a weapon ought to be zipcuffed. Another soldier asks about older girls and women. "They're old enough to fire weapons, but we're not going to be doing women like that," Kelley says. Handcuffing women is considered an insult in Arab society and the soldiers don't want to engender ill will. Alvarez, 26, of San Jose, California, leads the squad that will be first into the house. It will be his job to breach the door, putting him in the greatest danger by being first to confront anyone inside. Alvarez, who wants to join a police SWAT team - an elite police commando unit - when he leaves the service, says he's not afraid. "We're in the Army. This is what we do," he says, grinning from beneath a black watch cap pulled low just over his eyes. Just outside, four Stryker vehicles idle with their rear hatches open. The soldiers from Assassin Troop swill energy drinks or coffee and smoke. At 12:54 p.m., the Strykers leave the base. "Just remember. If something happens, eliminate the threat," Kelley tells them. "It ain't no one-man show. John Wayne and Clint Eastwood ain't in the Army." ___ The man who confronts Alvarez at the door of the first house does not resist. In seconds, he is zipcuffed and sprawled on the floor. Alvarez sweeps through the kitchen, past a mixing bowl filled with parsley and a pail of orange rinds in the sink. Into the living room, where a burning kerosene lantern illuminates a sleeping woman in her early 20s. She screams as Alvarez moves through a doorway to the bedroom where an old man sleeps with his wife and across into another living room. "First floor is clear," Alvarez says. Two soldiers charge up the stairs where they confront a 4-foot (1.2-meter) hatch that leads to another bedroom. They rush in, waking up a woman, a man and four children, including a teenage girl who begins sobbing "Oh, mama, mama" over and over. The family is shepherded downstairs to sit next to the old man, who has begun to rock back and forth, mutter and wheeze. "Second floor is clear," Staff Sgt. Michael Johnston, 29, of Basin, Wyoming, announces. Staff Sgt. Steven Doolittle, of Chelsea, Oklahoma, and the oldest man in the platoon at 32, tells the old man to be quiet. "He is my grandfather, he is sick. What do you want?" the young woman shouts in accented but flawless English. Doolittle is silent. Alvarez and his team head through the back garden to the house next door - where intelligence says the source's elderly acquaintance lives. US troops watching from other buildings have told him there is movement on both floors. Once inside, he radios for help. Wailing can be heard in the background. "We got the baby issue up here, we need personnel," Alvarez reports to Brogan. A few minutes later, the team returns to the first house with three women, two babies and a man who claims he worked for KBR, the Halliburton subsidiary, until a year ago, but quit because it was too dangerous. The man tells them he heard the commotion at his neighbor's house and opened his gate because he was afraid they would smash it down. The soldiers didn't find the informant's friend or his grandson. Doolittle brings the man they did find into the kitchen to kneel on the floor with two other males, one of whom is the son of the elderly man in the next room. Two bespectacled soldiers from the 172nd Stryker Brigade's intelligence unit, who ask not to be identified because of their work, approach the three men. "I need you to tell me: Has your father ever done anything with terrorists? Has he supported them? Has he told them what to do, has he even led to them?" one interrogator asks. The question is repeated in Arabic by a military translator. The man who says he once worked for KBR smiles, closes his eyes and shakes his head slowly, almost patiently. None of the three look particularly frightened, just tired. "He is a peaceful man who stands in the doorway and spends the day tending the garden," the KBR man says of the 75-year-old in the living room. Eberhart comes in from his command vehicle. He is not convinced. He suspects that the old man is not the financier, but the leader of the terrorist cell himself. Their names match, and the old man could be exaggerating his poor health. He could also be the quiet influence behind the cell, not directly involved in attacks. "You got to think mafia," Eberhart says. "The older you are the more respect you get." He orders the old man to be taken to a U.S. base and leaves the house to look for the man's third daughter who wasn't there with her two sisters when the soldiers broke in. She might know something more. Kelley has his men begin to search the house, slowly sifting through cabinets, drawers and closets. They come across the family's one weapon, a pistol, and collect nine $100 bills along with the equivalent of several hundred more dollars in Iraqi dinars. Yet as the search progresses, something doesn't seem right. The old man was in the first house, not the second. There is no one who fits the description of the financier, and no one who could be his college-age son. And the three men on the floor don't look much like bodyguards. All three men in zipcuffs deny owning a gas station. One says he is a civil engineer. Their identification cards back them up. The search turns up nothing suspicious. One seized document is a mimeograph copy of an English class reading: "Further examples about the basic patters in English: Palmer and Crystal ate the meat (hungrily) (in their hut) (that night)." As Brogan paces the room, a call comes in. It's Eberhart. He tells them to release everyone and get back into their Strykers. An intelligence officer back at headquarters has decided the old man doesn't match the cell leader's description. Kelley and his crew are told to return everything that has been collected and packed into a black plastic trunk, and leave. Sgt. Juan Castellanos, 26, of Willow Creek, California, lays out everything at the feet of the old man sitting in the living room, including the cash. Brogan orders his men into the room along with the three Iraqi men, who are cut free. They rub their wrists, inflamed and red from the zipcuffs. With his masked interpreter beside him, Brogan looks to the Iraqis and U.S. soldiers surrounding him. "We apologize for the inconvenience tonight. We had bad intelligence and believed there was terrorist activity here. All your items have been returned. We are not taking anyone tonight and we are returning all your items," he says. "Normally we get good intelligence and we catch the bad guys that are trying to hurt you guys. I hope that everyone is OK and we didn't cause any stress." One of the Iraqi men tells him gently that everyone just wants to go to bed and for the Americans to leave them in peace. Brogan nods. The teenage girl is still crying. Outside, a light rain still falls, but not enough to ground the Kiowa OH-58 scout helicopters that buzz overhead. Brogan's men climb into the Strykers. His attention turns to the radio. Eberhart has tracked down and woken up the third daughter and her story holds up. The tipster was wrong. The people in the two houses have no connection to the terror cell leader or its financier. Castellanos lights a cigarette as the Stryker lurches off. It is just before 3 a.m. "What a disappointing night," he says.