It was just after 11pm on the night of May 1st, two MH 60 Black Hawk helicopters lifted off from Jalalabad Air Field, in eastern Afghanistan, and embarked on a covert mission into Pakistan to kill Osama bin Laden. Inside the aircraft were twenty three Navy SEALs from the Naval Special Warfare Development Group, or DEVGRU. A Pakistani American translator, whom I will call Ahmed, and a dog named Cairo a Belgian Malinois were also aboard. It was a moonless evening, and the helicopters pilots, wearing night vision goggles, flew without lights over mountains that straddle the border with Pakistan. Radio communications were kept to a minimum, and an eerie calm settled inside the aircraft.

The helicopters ducked into an alpine valley and slipped, undetected, into Pakistani airspace. For more than sixty years, Pakistans military has maintained a state of high alert against its eastern neighbor, India. Because of this obsession, Pakistans "principal air defenses are all pointing east," Shuja Nawaz, an expert on the Pakistani Army and the author of "Crossed Swords: Pakistan, Its Army, and the Wars Within," told me. Senior defense and Administration officials concur with this assessment, but a Pakistani senior military official, whom I reached at his office, in Rawalpindi, disagreed. "No one leaves their borders unattended," he said. The Black Hawks, each of which had two pilots and a crewman from the 160th Special Operations Aviation Regiment, or the Night Stalkers, had been modified to mask heat, noise, and movement; the copters exteriors had sharp, flat angles and were covered with radar dampening "skin."

The SEALs destination was a house in the small city of Abbottabad, which is about a 120 miles across the Pakistan border. According to information gathered by the Central Intelligence Agency, bin Laden was holed up on the third floor of a house in a one acre compound just off Kakul Road in Bilal Town, a middle class neighborhood less than a mile from the entrance to the academy. If all went according to plan, the SEALs would drop from the helicopters into the compound, overpower bin Ladens guards, shoot and kill him at close range, and then take the corpse back to Afghanistan.

The helicopters traversed Mohmand, one of Pakistans seven tribal areas, skirted the north of Peshawar, and continued due east. The commander of DEVGRUs Red Squadron, whom I will call James, sat on the floor, squeezed among ten other SEALs, Ahmed, and Cairo. (The names of all the covert operators mentioned in this story have been changed.) James, a broad chested man in his late thirties, does not have the lithe swimmers frame that one might expect of a SEAL he is built more like a discus thrower. That night, he wore a shirt and trousers in Desert Digital Camouflage, and carried a silenced Sig Sauer P226 pistol, along with extra ammunition; a CamelBak, for hydration; and gel shots, for endurance. He held a short barrel, silenced M4 rifle. (Others SEALs had chosen the Heckler & Koch MP7.) A "blowout kit," for treating field trauma, was tucked into the small of Jamess back. Stuffed into one of his pockets was a laminated gridded map of the compound. In another pocket was a booklet with photographs and physical descriptions of the people suspected of being inside. He wore a noise cancelling headset, which blocked out nearly everything besides his heartbeat.

During the ninety minute helicopter flight, James and his teammates rehearsed the operation in their heads. Since the autumn of 2001, they had rotated through Afghanistan, Iraq, Yemen, and the Horn of Africa, at a brutal pace. At least three of the SEALs had participated in the sniper operation off the coast of Somalia, in April, 2009, that freed Richard Phillips, the captain of the Maersk Alabama, and left three pirates dead. In October, 2010, a DEVGRU team attempted to rescue Linda Norgrove, a Scottish aid worker who had been kidnapped in eastern Afghanistan by the Taliban. During a raid of a Taliban hideout, a SEAL tossed a grenade at an insurgent, not realizing that Norgrove was nearby. She died from the blast. The mistake haunted the SEALs who had been involved; three of them were subsequently expelled from DEVGRU.

The Abbottabad raid was not DEVGRUs maiden venture into Pakistan, either. The team had surreptitiously entered the country on ten to twelve previous occasions, according to a special operations officer who is deeply familiar with the bin Laden raid. Most of those missions were forays into North and South Waziristan, where many military and intelligence analysts had thought that bin Laden and other Al Qaeda leaders were hiding. (Only one such operation the September, 2008, raid of Angoor Ada, a village in South Waziristan has been widely reported.) Abbottabad was, by far, the farthest that DEVGRU had ventured into Pakistani territory. It also represented the teams first serious attempt since late 2001 at killing "Crankshaft" the target name that the Joint Special Operations Command, or JSOC, had given bin Laden. Since escaping that winter during a battle in the Tora Bora region of eastern Afghanistan, bin Laden had defied American efforts to trace him. Indeed, it remains unclear how he ended up living in Abbottabad.

Forty five minutes after the Black Hawks departed, four MH 47 Chinooks launched from the same runway in Jalalabad. Two of them flew to the border, staying on the Afghan side; the other two proceeded into Pakistan. Deploying four Chinooks was a last minute decision made after President Barack Obama said he wanted to feel assured that the Americans could "fight their way out of Pakistan." Twenty five additional SEALs from DEVGRU, pulled from a squadron stationed in Afghanistan, sat in the Chinooks that remained at the border; this "quick reaction force" would be called into action only if the mission went seriously wrong. The third and fourth Chinooks were each outfitted with a pair of M134 Miniguns. They followed the Black Hawks initial flight path but landed at a predetermined point on a dry riverbed in a wide, unpopulated valley in northwest Pakistan. The nearest house was half a mile away. On the ground, the copters rotors were kept whirring while operatives monitored the surrounding hills for encroaching Pakistani helicopters or fighter jets. One of the Chinooks was carrying fuel bladders, in case the other aircraft needed to refill their tanks.

Meanwhile, the two Black Hawks were quickly approaching Abbottabad from the northwest, hiding behind the mountains on the northernmost edge of the city. Then the pilots banked right and went south along a ridge that marks Abbottabads eastern perimeter. When those hills tapered off, the pilots curled right again, toward the city center, and made their final approach.

During the next four minutes, the interior of the Black Hawks rustled alive with the metallic cough of rounds being chambered. Mark, a master chief petty officer and the ranking noncommissioned officer on the operation, crouched on one knee beside the open door of the lead helicopter. He and the eleven other SEALs on "helo one," who were wearing gloves and had on night vision goggles, were preparing to fast rope into bin Ladens yard. They waited for the crew chief to give the signal to throw the rope. But, as the pilot passed over the compound, pulled into a high hover, and began lowering the aircraft, he felt the Black Hawk getting away from him. He sensed that they were going to crash.

When the helicopter began getting away from the pilot, he pulled back on the cyclic, which controls the pitch of the rotor blades, only to find the aircraft unresponsive. The high walls of the compound and the warm temperatures had caused the Black Hawk to descend inside its own rotor wash a hazardous aerodynamic situation known as "settling with power." In North Carolina, this potential problem had not become apparent, because the chain link fencing used in rehearsals had allowed air to flow freely. A former helicopter pilot with extensive special operations experience said of the pilots situation, "Its pretty spooky Ive been in it myself. The only way to get out of it is to push the cyclic forward and fly out of this vertical silo youre dropping through. That solution requires altitude. If youre settling with power at two thousand feet, youve got plenty of time to recover. If youre settling with power at fifty feet, youre going to hit the ground."

The pilot scrapped the plan to fast rope and focussed on getting the aircraft down. He aimed for an animal pen in the western section of the compound. The SEALs on board braced themselves as the tail rotor swung around, scraping the security wall. The pilot jammed the nose forward to drive it into the dirt and prevent his aircraft from rolling onto its side. Cows, chickens, and rabbits scurried. With the Black Hawk pitched at a forty five degree angle astride the wall, the crew sent a distress call to the idling Chinooks.

James and the SEALs in helo two watched all this while hovering over the compounds northeast corner. The second pilot, unsure whether his colleagues were taking fire or experiencing mechanical problems, ditched his plan to hover over the roof. Instead, he landed in a grassy field across the street from the house.

No American was yet inside the residential part of the compound. Mark and his team were inside a downed helicopter at one corner, while James and his team were at the opposite end. The teams had barely been on target for a minute, and the mission was already veering off course.

"Eternity is defined as the time be tween when you see something go awry and that first voice report," the special operations officer said. The officials in Washington viewed the aerial footage and waited anxiously to hear a military communication. The senior adviser to the President compared the experience to watching "the climax of a movie."

After a few minutes, the twelve SEALs inside helo one recovered their bearings and calmly relayed on the radio that they were proceeding with the raid. They had conducted so many operations over the past nine years that few things caught them off guard. In the months after the raid, the media have frequently suggested that the Abbottabad operation was as challenging as Operation Eagle Claw and the "Black Hawk Down" incident, but the senior Defense Department official told me that "this was not one of three missions. This was one of almost two thousand missions that have been conducted over the last couple of years, night after night." He likened the routine of evening raids to "mowing the lawn." On the night of May 1st alone, special operations forces based in Afghanistan conducted twelve other missions; according to the official, those operations captured or killed between fifteen and twenty targets. "Most of the missions take off and go left," he said. "This one took off and went right."

Minutes after hitting the ground, Mark and the other team members began streaming out the side doors of helo one. Mud sucked at their boots as they ran alongside a ten foot high wall that enclosed the animal pen. A three man demolition unit hustled ahead to the pens closed metal gate, reached into bags containing explosives, and placed C 4 charges on the hinges. After a loud bang, the door fell open. The nine other SEALs rushed forward, ending up in an alleylike driveway with their backs to the houses main entrance. They moved down the alley, silenced rifles pressed against their shoulders. Mark hung toward the rear as he established radio communications with the other team. At the end of the driveway, the Americans blew through yet another locked gate and stepped into a courtyard facing the guesthouse, where Abu Ahmed al Kuwaiti, bin Ladens courier, lived with his wife and four children.

Three SEALs in front broke off to clear the guesthouse as the remaining nine blasted through another gate and entered an inner courtyard, which faced the main house. When the smaller unit rounded the corner to face the doors of the guesthouse, they spotted Kuwaiti running inside to warn his wife and children. The Americans night vision goggles cast the scene in pixellated shades of emerald green. Kuwaiti, wearing a white shalwar kameez, had grabbed a weapon and was coming back outside when the SEALs opened fire and killed him.

The nine other SEALs, including Mark, formed three man units for clearing the inner courtyard. The Americans suspected that several more men were in the house: Kuwaitis thirty three year old brother, Abrar; bin Ladens sons Hamza and Khalid; and bin Laden himself. One SEAL unit had no sooner trod on the paved patio at the houses front entrance when Abrar a stocky, mustachioed man in a cream colored shalwar kameez appeared with an AK 47. He was shot in the chest and killed, as was his wife, Bushra, who was standing, unarmed, beside him.

Outside the compounds walls, Ahmed, the translator, patrolled the dirt road in front of bin Ladens house, as if he were a plainclothes Pakistani police officer. He looked the part, wearing a shalwar kameez atop a flak jacket. He, the dog Cairo, and four SEALs were responsible for closing off the perimeter of the house while James and six other SEALs the contingent that was supposed to have dropped onto the roof moved inside. For the team patrolling the perimeter, the first fifteen minutes passed without incident. Neighbors undoubtedly heard the low flying helicopters, the sound of one crashing, and the sporadic explosions and gunfire that ensued, but nobody came outside. One local took note of the tumult in a Twitter post: "Helicopter hovering above Abbottabad at 1 AM (is a rare event)."

Eventually, a few curious Pakistanis approached to inquire about the commotion on the other side of the wall. "Go back to your houses," Ahmed said, in Pashto, as Cairo stood watch. "There is a security operation under way." The locals went home, none of them suspecting that they had talked to an American. When journalists descended on Bilal Town in the coming days, one resident told a reporter, "I saw soldiers emerging from the helicopters and advancing toward the house. Some of them instructed us in chaste Pashto to turn off the lights and stay inside."

Meanwhile, James, the squadron commander, had breached one wall, crossed a section of the yard covered with trellises, breached a second wall, and joined up with the SEALs from helo one, who were entering the ground floor of the house. What happened next is not precisely clear. "I can tell you that there was a time period of almost twenty to twenty five minutes where we really didnt know just exactly what was going on," Panetta said later, on "PBS NewsHour."

Until this moment, the operation had been monitored by dozens of defense, intelligence, and Administration officials watching the drones video feed. The SEALs were not wearing helmet cams, contrary to a widely cited report by CBS. None of them had any previous knowledge of the houses floor plan, and they were further jostled by the awareness that they were possibly minutes away from ending the costliest manhunt in American history; as a result, some of their recollections on which this account is based may be imprecise and, thus, subject to dispute.

As Abrars children ran for cover, the SEALs began clearing the first floor of the main house, room by room. Though the Americans had thought that the house might be booby trapped, the presence of kids at the compound suggested otherwise. "You can only be hyper vigilant for so long," the special operations officer said. "Did bin Laden go to sleep every night thinking, The next night theyre coming? Of course not. Maybe for the first year or two. But not now." Nevertheless, security precautions were in place. A locked metal gate blocked the base of the staircase leading to the second floor, making the downstairs room feel like a cage.

After blasting through the gate with C 4 charges, three SEALs marched up the stairs. Midway up, they saw bin Ladens twenty three year old son, Khalid, craning his neck around the corner. He then appeared at the top of the staircase with an AK 47. Khalid, who wore a white T shirt with an overstretched neckline and had short hair and a clipped beard, fired down at the Americans. (The counterterrorism official claims that Khalid was unarmed, though still a threat worth taking seriously. "You have an adult male, late at night, in the dark, coming down the stairs at you in an Al Qaeda house your assumption is that youre encountering a hostile.") At least two of the SEALs shot back and killed Khalid. According to the booklets that the SEALs carried, up to five adult males were living inside the compound. Three of them were now dead; the fourth, bin Ladens son Hamza, was not on the premises. The final person was bin Laden.

Before the mission commenced, the SEALs had created a checklist of code words that had a Native American theme. Each code word represented a different stage of the mission: leaving Jalalabad, entering Pakistan, approaching the compound, and so on. "Geronimo" was to signify that bin Laden had been found.

Three SEALs shuttled past Khalids body and blew open another metal cage, which obstructed the staircase leading to the third floor. Bounding up the unlit stairs, they scanned the railed landing. On the top stair, the lead SEAL swivelled right; with his night vision goggles, he discerned that a tall, rangy man with a fist length beard was peeking out from behind a bedroom door, ten feet away. The SEAL instantly sensed that it was Crankshaft. (The counterterrorism official asserts that the SEAL first saw bin Laden on the landing, and fired but missed.)

The Americans hurried toward the bedroom door. The first SEAL pushed it open. Two of bin Ladens wives had placed themselves in front of him. Amal al Fatah, bin Ladens fifth wife, was screaming in Arabic. She motioned as if she were going to charge; the SEAL lowered his sights and shot her once, in the calf. Fearing that one or both women were wearing suicide jackets, he stepped forward, wrapped them in a bear hug, and drove them aside. He would almost certainly have been killed had they blown themselves up, but by blanketing them he would have absorbed some of the blast and potentially saved the two SEALs behind him. In the end, neither woman was wearing an explosive vest.

A second SEAL stepped into the room and trained the infrared laser of his M4 on bin Ladens chest. The Al Qaeda chief, who was wearing a tan shalwar kameez and a prayer cap on his head, froze; he was unarmed. "There was never any question of detaining or capturing him it wasnt a split second decision. No one wanted detainees," the special operations officer told me. (The Administration maintains that had bin Laden immediately surrendered he could have been taken alive.) Nine years, seven months, and twenty days after September 11th, an American was a trigger pull from ending bin Ladens life. The first round, a 5.56 mm. bullet, struck bin Laden in the chest. As he fell backward, the SEAL fired a second round into his head, just above his left eye. On his radio, he reported, "For God and country Geronimo, Geronimo, Geronimo." After a pause, he added, "Geronimo E.K.I.A." "enemy killed in action."

Hearing this at the White House, Obama pursed his lips, and said solemnly, to no one in particular, "We got him."