Viewed backwards, from Osama bin Laden's hideout to the scraps of intelligence that led to it, the trail seems obvious. Tracing it from end to beginning obscures the level of difficulty: the years of frustration and patient effort, the technological innovation, the lives lost, the mistakes made, the money spent. The trail to Abbottabad represented a triumph of dot connecting. In this case, it began with a name. It was not even a real name, and the reference was to someone reported, falsely, to be dead.

The name Abu Ahmed al-Kuwaiti was first mentioned to authorities in Mauritania by an al-Qaida operative, Mohamedou Ould Salahi. It was obviously a pseudonym. The name meant "the Father of Ahmed from Kuwait". It was just one name among thousands that were daily being entered into what would become the Terrorism Information Awareness database.

The same pseudonym, and person, would be fleshed out in more detail by three more detainees. A fourth, Abu Faraj al-Libi, al-Qaida's number three, who was captured in May 2005, said he had never heard of him. That was interesting. Five different detainees had been asked about him. Four said they knew of him. Three placed him close to Bin Laden, one named him as a "courier" (although one of those three said he was dead) and one, Khalid Sheikh Mohammed, also a senior figure, said he had left al-Qaida. Here's what the analysts gathered: their two most important captives either minimised the importance of the Kuwaiti or denied his existence altogether. This might mean that Ahmed the Kuwaiti was very important indeed. Add the fact that the Kuwaiti had dropped off the map… just like Bin Laden. For the first time, the CIA teams began to consider that the Kuwaiti was with "the Sheikh" even now.

In 2007, the agency learned that the Kuwaiti's real name was Ibrahim Saeed Ahmed. He came from a large Pakistani family that had moved to Kuwait. He and his brothers had grown up speaking Pashto and Arabic. One of his brothers had been killed fighting against the Soviets in Afghanistan. In June 2010, because of either some change in his cell phone or its service package, or some improvement in their own capability, the US was able to pinpoint Ahmed's phone's location when it was in use. This meant they could find the Kuwaiti, and watch him.

Ahmed and his family lived in a large compound in Abbottabad, with his brother Abrar and his family. They went by assumed names in the neighbourhood; Ibrahim called himself Arshad Khan and his brother went by the name Tariq Khan. Both had been born in Kuwait, but ethnically they were tall, fair-skinned, bearded Pakistani Pashtuns. They had never been wealthy, but their compound appeared extremely pricey. And in addition to the high walls, it seemed that the brothers observed extraordinarily strict security measures. Other than to attend the local religious school or to visit a doctor, none of their children left the compound. In telephone calls to other far-flung family members, always made from locations distant from the compound itself, they lied about where they were living.

The agency had been investigating the compound quietly, snapping pictures from above and spying on it with agents on the ground – who couldn't see inside, but who asked casual questions of those living nearby, always careful not to appear too curious. Who lives in that big place? I wonder what the people who live there do? That and telephone intercepts produced two discoveries that the agency considered greatly significant, and that persuaded CIA director Leon Panetta he ought to bring the discovery to the president.

The first was that living inside the compound on the upper two floors of the big house was a third family. No member of that family ever left the grounds. Its children did not even leave to attend school with the others. And there were signs that the brothers, who ostensibly owned the place, served this hidden family.

The second discovery was that Ibrahim Ahmed was apparently still working for al-Qaida. In a telephone conversation with an old friend that summer, Ahmed was peppered with the standard questions – "What are you doing now? What are you up to?" At first he didn't answer. But his friend was insistent, and he finally gave in, albeit cryptically. "I'm with the same ones as before," he said. His friend seemed to know immediately what that meant and, after uttering, "May Allah be with you", dropped the subject. That suggested that whomever Ahmed and his brother were minding in Abbottabad belonged to al-Qaida.

Panetta brought two of the agency's Bin Laden team leaders with him to the Oval Office. The lead analyst, who would become known as "John" (his middle name), had devoted himself to the hunt for most of the previous 10 years. The agency men walked the president and his deputy national security adviser, Thomas Donilon, through the reverse engineering that had helped them identify "Ahmed the Kuwaiti" and the suspicious nature of the compound itself. Panetta compared Abbottabad to a well-to-do northern Virginia suburb. The compound was eight times larger than any of the surrounding residences. Its walls were built unusually high, topped by 2ft of barbed wire. There was no way to see inside the house itself, from the ground or from above. The windows were made of reflective glass or had been coated to achieve the same effect.

Obama was familiar enough with Bin Laden's background to have long ago stopped picturing him crouched in a cave or living in some sparse mountaintop camp. But to find him in a sprawling compound in an affluent neighbourhood – they were all surprised by that. Still, the president wasn't especially hopeful. The connection to Bin Laden was tenuous at best. He encouraged Panetta to press on. He wanted the identity of the hidden family nailed down. He also wanted a "close hold" on the lead, meaning it was not to leave his office.

"Just emotionally," Obama told me, "I was not particularly optimistic about it. I mean, I think my general view was, OK, these guys are carrying out my orders to pursue every lead. Did I think at that stage that we had the goods? I think I was pretty guarded about not letting myself get overly excited about the prospects."

Only one member of the hidden family in Abbottabad could be seen regularly, a tall man in traditional Pashtun dress and prayer cap who took daily walks inside the compound walls. Overhead cameras were able to get images of him, but they were not very good. He appeared to be tall and thin. They called the man "the Pacer".

The CIA determined that the hidden family was large: three wives, a young man and 10 or more children, several of them teenagers or young adults. The number of wives and children corresponded with their theorising about who might surround Bin Laden on the run. He had always kept most of his family with him.

Obama was struck, as others were, by actually being able to see the mystery man.

"At this point, you're saying to yourself, this is all circumstantial, but it's hard to figure out what the explanation would be for that particular pattern," Obama said. "And so at that point I think there's a part of me that's thinking this might be for real." Still, the president was cautious. He instructed Panetta to figure out a way to nail it down. He said to continue keeping a tight lid on it. And he also instructed Panetta to start preparing options for action.

Planning for either an air or a ground assault on the compound proceeded through February 2011, ready for a meeting with Obama on 14 March. It was time to start making important decisions.

By early March, the agency had determined that the Abbottabad compound held a "high value target" and that it was most likely Osama bin Laden. "John", the team leader at the CIA, was close to convinced. He put his confidence level at 95%. Others were less certain. Some were as low as 40% or even 30%.

Ever since the agency's erroneous call, a decade earlier, that Saddam Hussein was hiding weapons of mass destruction, the CIA had instituted an almost comically elaborate process for weighing certainty. Analysts up and down the chain were now asked not only for their opinion, but to assign it a confidence level. Michael Morell, deputy director of the CIA, had been personally involved in the finding about Saddam's supposed weapons of mass destruction, and had felt more certain about that than he felt about this.

"Mr President, if we had a human source who had told us directly that Bin Laden was living in that compound, I still wouldn't be above 60%." Morell said he had spent a lot of time on both questions – WMDs and Abbottabad. "And I'm telling you, the case for WMDs wasn't just stronger, it was much stronger," he said.

The president listened, but he had already pretty much made up his mind. "One of the things you learn as president is you're always dealing with probabilities," he told me. "No issue comes to my desk that is perfectly solvable... Because if people were absolutely certain, then it would have been decided by somebody else... In this situation, what you started getting was probabilities that disguised uncertainty as opposed to actually providing you with more useful information."

Obama had no trouble admitting it to himself. If he acted on this, he was going to be taking a gamble, pure and simple. A big gamble.

"This is 50-50," he said. "Look, guys, this is a flip of the coin. I can't base this decision on the notion that we have any greater certainty than that."

So, if he decided to act, what were his options? Obama was presented with two. The simplest, and the one that posed the least risk to US forces, was to reduce the compound to dust, along with everyone and everything in and around it. To do the job right, the air force had calculated that would mean raining as many as 30 or more precision bombs from a high-flying B-2, or launching a comparable number of missiles.

A video seized from the compound in Abbottabad shows a man believed to be Osama bin Laden watching the US president on television. Photograph: AP

Obama asked how many people were living at the compound and was informed that there were four adult males, five women and nearly 20 children. He asked about the houses that were close to the compound. Those, too, would be completely destroyed, along with every resident man, woman and child. This really gave the president pause. America was not going to obliterate them on a 50-50 chance of also killing Osama bin Laden.

So the president scrapped that plan immediately. Then Vice Admiral William McRaven, commander of joint special operations command, explained the ground option for the first time. His team had not yet fleshed out the mission completely. One thing he could tell the president for sure was that if his team could be delivered to the compound, they could clear it and kill or capture Bin Laden with minimal loss of life.

Two weeks later, at the end of March, McRaven was back in the Situation Room with a full plan. The air force also came back with a plan for smaller bombs and smaller blast circles. They could hit the compound without harming people living in homes outside its walls, but the lesser assault meant they could not guarantee taking out anything underground. There would still be a lot of bodies, women and children included, and no way to tell if one of the dead was Bin Laden.

But there was another air option, one that appealed especially to Vice Chairman James Cartwright, one of Obama's favourite generals. Cartwright's new proposal for Abbottabad was to target the Pacer alone. Wait for the tall man to emerge for his daily exercise around the vegetable garden and shoot him down with a small missile fired from a drone.

It felt too good to be true. What if it worked and you dropped the Pacer in his tracks? How would you know that you had killed Osama bin Laden? And it was strictly a one-shot deal. If you missed, the Pacer and his entourage would vanish.

McRaven said that his team would be ready to conduct the raid by the first week of May, when the moon would vanish for a few days over Abbottabad. Obama told McRaven to start full dress rehearsals. He also told Cartwright to get ready to attempt the drone strike. He wanted both options kept alive until he made a decision.

Raiding the compound was the riskiest option. It posed a slew of hard questions that the air option did not. One of the most interesting was what to do if Bin Laden was not killed but captured. In the unlikely event that Bin Laden surrendered, Obama saw an opportunity to resurrect the idea of a criminal trial.

"We worked through the sort of legal and political issues that would have been involved, and Congress and the desire to send him to Guantánamo, and to not try him, and Article Three," the president told me. "I mean, we had worked through a whole bunch of those scenarios. But, frankly, my belief was if we had captured him, that I would be in a pretty strong position, politically, here, to argue that displaying due process and rule of law would be our best weapon against al-Qaida, in preventing him from appearing as a martyr."

Obama added, "I think it's important to emphasise, having made those plans, our expectation was that if, in fact, he was there, that he would go down fighting."

The final meeting was held in the Situation Room on the afternoon of Thursday 28 April. Popular accounts of this decisive session have portrayed Obama facing down a wall of opposition and doubt among his top advisers. In fact, there was overwhelming support for launching the raid.

One by one, the principals around the room were asked to choose one of the three options: the raid, the missile strike or doing nothing – and then to defend their choice. The only major dissenters were Joe Biden and defence secretary Robert Gates, and, by the next morning, Gates had changed his mind. Everyone else favoured sending in the Seals. At first it didn't seem like Hillary Clinton would. She had famously faulted Obama years earlier for asserting that he would take a shot in Pakistan unilaterally if there was a good chance of getting Bin Laden and now, as secretary of state, she would bear the brunt of the diplomatic fallout if he did. Suspense built as Clinton worked her way around to her surprising bottom line. They could not ignore a chance to get Osama bin Laden. It was too important to the country. It outweighed the risks.

The Thursday meeting ended early in the evening. "You'll have my decision in the morning," Obama said.

In truth, as the president told me, he had all but made up his mind when he left the Thursday meeting. He had been thinking about it for months. The advantages of the raid were obvious and, to his way of thinking, outweighed the risks. A missile might go astray and, unlike taking a shot from a drone, the raid offered certainty. If Bin Laden was there, they would know it and they would bring him out, dead or alive.

There was another compelling reason to send in the Seal team. If this had been Bin Laden's hideout for years, it might hold a trove of valuable information, perhaps the kind that would enable the US to further dismantle al-Qaida.

He reviewed the process over and over again in his mind Thursday night into Friday morning. His habit was to stay up much later than Michelle and his girls. They had turned in at 10 o'clock. He was up another three hours, pacing and thinking in the Treaty Room, the upstairs room that functions as the family's living room and also the president's private office.

"It was a matter of taking one last breath and just making sure, asking is there something that I haven't thought of?" Obama explained to me. "Is there something that we need to do?"

The questions stayed with him even as he tried to sleep that night. He believed that waiting longer would not accomplish anything, and might risk everything. They were not likely to get better intelligence, that had been clear.

On Friday morning, before he walked out to the South Lawn to board a helicopter on a trip to the southern states to view tornado damage, he called a meeting. "It's a go," Obama said. "We're going to do the raid. Prepare the directives."

McRaven's men were in Jalalabad, poised. The earliest they would go would be early the following evening, Saturday 30 April. Most of the 24 handpicked team were members of Red Squadron of Seal Team Six. Behind this initial force were the men and choppers and planes that McRaven hoped he would not need. There were three MH-47E Chinooks, big as tractor trailers, with flat rotors front and back. Also on alert were the fighters and combat-control aircraft that might be needed to fend off Pakistani fighters and ground-to-air defences.

There had been some conversation the evening before about the timing. The correspondents' dinner was the major black-tie social gala of the year in Washington: televised, and attended by celebrities from Hollywood and the sports world, and by all of the most prominent government leaders and journalists. The main attraction was always the president of the United States, who typically delivered a standup comedy routine poking fun at himself and the press. If Obama chose the raid, it would likely take place at the same time as the dinner. How would it look for the president to be making jokes at a podium while the men were risking their lives? And what if something went wrong and everyone had to suddenly leave the party? When someone floated the idea of asking McRaven to postpone the mission for a day, Clinton had heard enough.

"We are not going to let a White House correspondents' dinner drive an operational decision," she said.

That ended it. Obama told Donilon, "Tom, if it turns out that's when we decide to go, you'll just tell them I have a stomach ache and I have to bow out."

The question of what to do about the dinner became moot when McRaven's weather experts predicted fog in the Abbottabad area for Saturday night, so he decided to push the mission back one day. They would launch on Sunday night.

So in this tense moment, the most suspenseful of Obama's presidency, he and his staff dressed for a formal party. Obama lived up to his reputation for cool. If he was anxious about the next day's mission, he didn't show it, garnering laughs as he poked fun at the long-running dispute over his origins and his own sometimes messianic public image.

Great care was taken to preserve the appearance of normality on Sunday. President Obama left for his weekly golf outing at Andrews Air Force Base, but this time he would play only nine holes.

Arrival times at the White House for all the top staffers and cabinet members were staggered. The West Wing tours normally booked for Sunday had been cancelled. Obama's personal secretary had planned one for that day, intending to show around the cast members of the hit movie The Hangover, who had come to town for the previous night's gala, but was told there were no exceptions.

White House staffers watch events in Abbottabad unfold via video link. Photograph: White House/Pete Souza

In the Situation Room and the complex of small meeting rooms around it, staffers worked on setting up the video conferencing. Panetta, who would officially command the mission from his conference room at the CIA HQ in Langley, would be up on the big screen, relaying the running commentary of McRaven, who would be at his post in Jalalabad. High over Abbottabad was an RQ-170 Sentinel, a stealthy drone with a high-powered lens, which would provide a live video feed of the assault.

Two stealth Black Hawks lifted off from the airfield at Jalalabad precisely at 11pm local time. They were blacked out and both carried a full, minutely calculated load. Each of the Seals was in full kit. They carried only light arms because the compound was not heavily defended.

About 10 minutes into the flight, the choppers rose above a series of rugged peaks and crossed into Pakistan. As soon as they did, the three big Chinooks lifted off from Jalalabad. One would set down just inside the border on the Afghan side; the other two would proceed to the staging area north of Abbottabad by a different route.

Up on the big screen in the White House Situation Room, Panetta read out occasional updates on the choppers' progress. One of Obama's aides said, "Mr President, this is going to take a while, you might not want to sit here and watch the whole thing unfold."

"No, I think I'm going to go ahead and watch," Obama said.

Approaching the compound from the north-west, the Black Hawks were now visible in the grainy overhead feed from the Sentinel. After that, things happened very fast.

Everyone watched with shock as the first chopper, instead of hovering over the compound as planned, to drop the Seal team from ropes and then move off, abruptly wheeled, clipping the compound wall with its tail and hitting the ground. This clearly wasn't good.

The Night Stalker pilot had tried to bring his Black Hawk to a hover, but the chopper wouldn't perform the manoeuvre. It began to skid uncontrollably. The pilot of the faltering Black Hawk moved with practised speed. The landing was hard, but upright, which was key.

No one watching the small screen in the White House could see exactly what had happened. They could see only that it was down inside the compound. They knew that was not the plan. Here in the first seconds of the mission, they had a Black Hawk down. Obama had been receiving mission updates secondhand, talking with Panetta via the video hook-up in the Situation Room, and letting others monitor the video feed and chat lines in the side room, but when the chopper went down, he abruptly got up and crossed the hall.

"I'll just take this chair here," he said, sliding into the corner. "I need to watch this."

Clinton followed and took one of the remaining chairs at the table. Other staffers began crowding into the small room to see what would happen next. Obama's face was etched with worry. A White House photographer snapped a picture of the now-crowded side room that would become famous.

When the first chopper went down, the second Black Hawk diverted from its planned course and landed outside the compound walls in a newly planted field. It seemed to the viewers that the entire assault plan had gone awry.

Then, abruptly, Seals began streaming out of both choppers, inside the compound and out. The assault was on. The team from the crashed chopper moved quickly along the inside wall of the compound, pausing only to blow open a metal door that led to the house. The team from the chopper outside the wall blasted in through another entrance. There were flashes of light on the screen. The men were moving on the house itself now, and then were inside.

Upstairs in that house, according to accounts given by Bin Laden's family, the household had been startled awake by a loud crash. Bin Laden instructed his wife, Amal, to leave the lights off. They would not have been able to turn them on anyway, because in advance of the assault CIA operatives had cut off electricity to the entire neighbourhood.

One group of Seals entered the garage area of the guest house. There was a single brief spray of gunfire as they approached, but it was wild and ineffective. It had most likely come from the courier Ibrahim Saeed Ahmed – Ahmed the Kuwaiti. The Seals returned fire, killing Ahmed and wounding his wife in the shoulder.

Another part of the team moved on the main house, clearing it methodically. Abrar Ahmed, the courier's brother, was in a first-floor bedroom with his wife, Bushra. Both were shot dead. They cleared the first floor room by room, encountering no further gunfire. They passed through two large storage rooms and a kitchen. No one knew the layout of the interior. When they encountered a locked metal door in the rear, sealing off a stairway to the upper floors, they slapped on a small C-4 charge, blew it off its hinges and moved up the stairs. Bin Laden's 23-year-old son, Khalid, a slender, bearded man wearing a white T-shirt, was shot dead at the top. There were wailing women and children on this floor, none of whom posed a threat. The team didn't know it yet, but there was only one adult male left in the compound, and he was in the third-floor bedroom.

Originally, half the assaulting Seals were to have come down through the balcony into the third floor, in which case Bin Laden would have been encountered immediately, at about the same time the Ahmed brothers were being shot downstairs. Instead, he had about 15 long minutes to wait in the darkness as the Seals methodically approached. The assaulters blew off the door barring the third floor and he would have heard men ascending, coming for him.

Three Seals came up those stairs, scanning different angles, searching while protecting each other. According to one of the Seals, the first man up spotted a tall, bearded, swarthy man in a prayer cap wearing traditional flowing Pakistani clothes, the knee-length shirt worn over pyjama-like bottoms. One or more of the Seals fired at him. The man retreated quickly into a bedroom and the Seals followed. In the bedroom they found two women leaning over a fatally wounded Bin Laden, who had been shot in the head. The first Seal violently moved the women out of the way and the other two stood over him and fired several more shots into his chest.

The engagement was over in seconds. Amal had been shot in the leg. Bin Laden had weapons on a shelf in his bedroom but had not picked them up. His identity was unmistakable, even with the grotesque hole through his right forehead.

McRaven heard "for God and country, pass Geronimo. Geronimo. Geronimo." The word "Geronimo" was part of a coded "mission execution checklist". It meant the critical milestone of the raid had been passed successfully, securing Bin Laden. McRaven conveyed the report immediately to Panetta, and it began to spread waves of excitement through the CIA and White House.

In the White House, in the corner of the small, crowded conference room, Obama heard "Geronimo ID'd". The president knew the ID was still tentative, so he didn't let himself fully believe it. But after McRaven had passed that along, it occurred to him that he had not asked specifically whether Bin Laden had been killed or captured. So he asked, "Find out whether it's Geronimo EKIA [Enemy Killed In Action]."

The answer came back, "Roger, Geronimo EKIA."

"Looks like we got him," said Obama, only half believing it.

The delay between these two reports would cause some confusion in later accounts, which suggested that the Seals had first found Bin Laden, chased him and then, a few minutes later, killed him. The finding and the shooting had happened in the time it took the three Seals to crash into his room. Eighteen minutes had elapsed since the choppers had arrived.

Bulldozers demolish the Abbottabad compound where Bin Laden is believed to have been in hiding for up to six years. Photograph: Aamir Qureshi/AFP/Getty Images

The video on the screen now showed Seals emerging from the house, herding the uninjured women and children to one corner of the compound, away from the downed chopper. Some of the men came out carrying a body bag – Bin Laden's body had been dragged feet-first down the stairs, leaving a bloody trail. The Seals eventually zipped it into a nylon bag. The assaulters moved deliberately, and Obama felt they were taking too long. Everyone was waiting for the Pakistani response at this point. The president just wanted them in the air.

Upstairs, Seals were hastily bagging Bin Laden's papers and computer, discs, flash drives, anything that might contain useful intelligence. Bin Laden's youngest wife, Amal, wounded, was helped down the stairs, and once outside started haranguing the Americans in Arabic. All four men who had lived in the compound, along with one woman, were dead. The surviving women and children were flex-cuffed. The women assumed they were going to be taken away. Questioned by an Arabic-speaking Seal, the women confirmed that they had killed "the Sheikh". One of the children confirmed that it was Osama bin Laden.

The Chinook summoned by McRaven now landed noisily outside the compound walls. Men were working on planting explosives on the downed Black Hawk and destroying its secret avionics with a hammer. A medic from the Chinook unzipped Bin Laden's body bag, took swabs of blood and inserted needles to extract bone marrow for DNA testing. Twenty more minutes elapsed before the body bag was carried out to the Black Hawk. One of the bone marrow samples was placed on the Chinook. The intelligence haul was likewise distributed between the two choppers.

Finally, the White House audience saw the downed Black Hawk explode with the set charges. The demolition team scurried to the Chinook and the choppers lifted off, leaving behind a huge blaze, a stunned collection of cuffed women and children, and four bodies. A photo purporting to be the bloody corpse of Khalid bin Laden would turn up on the internet in the coming days.

The choppers landed back in Jalalabad at 3am local time. None of the men who went on the raid had been hurt. They had lost a helicopter, but they had avoided Pakistan's defences completely. And they had killed Osama bin Laden.

The Seals were certain of it, but the White House and the world would demand more proof. The body bag was unzipped, and photographs were taken and transmitted immediately to Washington and Langley. The man had been dead for an hour and 40 minutes, and he had taken a shot to the head, so the face was swollen and distorted.

McRaven called CIA headquarters with a question for the Bin Laden team.

"How tall is this guy?" he asked.

He was told, "Between six-four and six-five."

The dead man was certainly tall, but no one had a tape measure, so one of the Seals who was exactly 6ft 4in lay down next to the body. It was roughly the same height.

Early on Sunday evening in Washington, Obama surveyed the first photos with other members of the team. When McRaven returned to his command centre, Obama asked him, "What do you think?"

"Without DNA I can't tell you I'm 100% sure," the admiral said. "But I'm pretty damned sure."

Still, the president was inclined to be cautious. It wasn't until 11.35pm that the president appeared on television, striding up the red carpet towards a podium, and began: "Good evening. Tonight, I can report to the American people and to the world that the United States has conducted an operation that killed Osama bin Laden, the leader of al-Qaida, and a terrorist who is responsible for the murder of thousands of innocent men, women and children."

In the days after the raid, an album of photographs was delivered to the White House, a series of shots of the dead Bin Laden. There would be much discussion that week about whether these images should be made public, as proof of death, but the president had firmly decided that they would not.

After much discussion and advice, it had been decided that the best option would be burial at sea. That way, there would be no shrine for the martyr's misguided followers. So the body was washed, photographed from every conceivable angle and flown on a V-22 Osprey to the aircraft carrier USS Carl Vinson, cruising in the North Arabian Sea. Procedures for a simple Muslim burial were performed on the carrier. The body was wrapped in a white shroud with weights to sink it.

The last sequence of colour photos in the death album were not grotesque. They were strangely moving. A navy photographer recorded the burial in full sunlight on Monday morning, 2 May. One frame shows the body wrapped in the weighted white shroud. The next shows it diagonal on a flat board, feet overboard. In the next frame the body is hitting the water with a small splash. In the next it is visible just below the surface, a ghostly torpedo descending. In the next shot there are only circular ripples on the blue surface. In the final frame the waters are calm.

The mortal remains of Osama bin Laden were gone for good.

• This is an edited extract from The Finish: The Killing Of Osama Bin Laden, by Mark Bowden, published next week by Atlantic Books at £20. To order a copy for £16, with free UK p&p, go to guardian.co.uk/bookshop or call 0330 333 6846.