The Snowden Files: The Inside Story of the World's Most Wanted Man

3 THE SOURCE

From the top of Sugar Loaf Mountain, the city of Rio de Janeiro appears as a precipitous swirl of greens and browns. In the sky, black vultures turn in slow spirals. Below – far below – is downtown and a shimmer of skyscrapers. Fringing it are beaches and breakers frothing endlessly on a turquoise sea. Standing above, arms outstretched, is the art deco statue of Christ the Redeemer.

Rio’s famous beaches, Copacabana and Ipanema, lie at either side of a claw-shaped stretch of coast. Copacabana has long enjoyed a louche reputation. And yes, there are lewd sand sculptures of skimpily dressed women with big buttocks, next to green-yellow-blue-white Brazilian flags. But these days Copacabana is more of a hangout for the geriatric rich. Few others can afford to live in the luxury flats overlooking this dreamy Atlantic coast.

On weekday mornings, residents emerge, stretch, and walk their pampered pooches. Skateboarders trundle along a cycle lane; there are juice bars, restaurants, pavement cafes. Over on the beach tanned locals play football – Brazil’s national obsession – or volleyball. Much of human life is here, sitting in the balmy days of winter under the rubber trees. But the girl from Ipanema is a rare sight. You are more likely to encounter her granny.

From Rio’s south-western district of Gávea, the road twists sharply up into Floresta da Tijuca, the world’s biggest urban forest, home to capuchin monkeys and toucans. It’s usually several degrees cooler than the sea-level beaches. Keep going and you eventually arrive at a secluded mountain home. Is it some sort of dog sanctuary? A sign on the metal gate proclaims ‘Cuidado Com O Cão’: beware of the dog. The warning is superfluous: from the house comes a wild yapping and yowling. The dogs – small ones, big ones, black ones, dun ones – greet visitors by pawing at their legs; dog droppings litter a tropical yard; a mountain stream gurgles alongside. If there is mutt heaven, this is surely it.

The house’s non-dog denizen is Glenn Greenwald. Greenwald, aged 46, is one of the more prominent US political commentators of his generation. Well before the Snowden story made him a household name, Greenwald had built up a following. A litigator by profession, he spent a decade working in the federal and state court system. The son of Jewish parents, truculent, gay, radical and passionate about civil liberties, Greenwald found his voice in the Bush era. In 2005 he gave up his practice to concentrate on writing full time. His online blog attracted a wide readership. From 2007 he contributed to Salon.com as a columnist.

From his home in Rio, Greenwald frequently appears as a pundit on US TV networks. This means driving down the mountain in his red Kia (which smells of dog) to a studio in the city’s hippodrome. Security staff greet him warmly in Portuguese – he speaks it fluently. The studio has a camera, a chair and a desk. Seated at the desk, the camera depicts him in the uniform of a killer lawyer: clean shirt, smart jacket, tie. Under the table, and unseen by his audience in New York or Seattle, Greenwald will wear flip-flops and a pair of beach shorts.

This hybrid outfit bespeaks a wider duality, between private and professional. In his private life, Greenwald is soft-hearted. He is obviously a sucker for distressed beasts; he and his partner David Miranda have scooped up 10 strays. They also dog-sit other people’s and keep an additional cat. Greenwald and Miranda met when the journalist came to Rio for a two-month holiday in 2005; it was Greenwald’s second day in town, and he was lying on the beach. They quickly fell in love; Greenwald says he lives in Miranda’s Brazilian coastal home city because US federal law refused to recognise same-sex marriages. (It does now). Miranda works as Greenwald’s journalist-assistant. And when you meet him, Greenwald is mild, easy to get along with, chatty and kind.

Professionally, though, Greenwald is a different creature: adversarial, remorseless, sardonic and forensic. He is a relentless pricker of what he regards as official US hypocrisy. Greenwald has been a waspish critic of the George W Bush administration, and of Obama. He is scathing of Washington’s record. Citizens’ rights, drone strikes, foreign wars, the US’s disastrous engagement with the Muslim world, Guantanamo Bay, America’s ‘global torture regime’ – all have been subjects for Greenwald’s Swiftian pen. In long, sometimes torrential posts, he has chronicled the US government’s alleged crimes around the world. Greenwald’s outspoken views on privacy make him arguably America’s best-known critic of government surveillance.

Fans view him as a radical hero in the revolutionary tradition of Thomas Paine. Enemies regard him as an irritant, an ‘activist’, even a traitor. Two of his books cover the foreign policy and executive abuses of the Bush era. A third, With Liberty and Justice for Some (2011), examines the double standards in America’s criminal justice system. Greenwald argues persuasively that there is one rule for the powerless and another for those in high office who break the law, and invariably get away with it. The book delves into a theme important to both Greenwald and Snowden: the illegal wiretapping scandal in the Bush White House, and the fact that nobody was ever punished for it.

In August 2012, Greenwald left Salon.com and joined the Guardian as a freelance columnist. It was a nice fit. The paper’s editor, Alan Rusbridger, sees the Guardian as inhabiting an editorial space distinct from most American newspapers – with less reverence for the notions of professional demarcation and detachment that, rightly or wrongly, shape much US journalism. More than most media outlets, the Guardian has embraced new digital technologies that have radically disrupted the old order.

Rusbridger observes: ‘We have, I think, been more receptive to the argument that newspapers can give a better account of the world by bringing together the multiple voices – by no means all of them conventional journalists – who now publish on many different platforms and in a great variety of styles. That’s how Greenwald ended up on the Guardian.’

Greenwald thus personifies a debate over what it means to be a journalist in the 21st century, in a new and noisy world of digital self-publishing, teeming with bloggers, citizen reporters and Twitter. Some have called this digital ecosystem outside mainstream publishing ‘the Fifth Estate’, in contrast to the establishment Fourth. Hollywood even used the name for a movie about WikiLeaks.

However, Rusbridger adds: ‘Greenwald does not much like being described as a member of the Fifth Estate – largely because there’s a persistent attempt by people in politics and the law as well as journalism to limit protections (for example, over sources or secrets) to people they regard (but struggle to define) as bona fide journalists. But he recognisably does have a foot in both camps, old and new.’

For sure, Greenwald believes in a partisan approach to journalism – but one, he says, that is grounded in facts, evidence and verifiable data. Typically he uses detail to smite his opponents, prising corrections from temples of US fact-checking, such as the Washington Post and the New York Times.

In an illuminating conversation with Bill Keller, a former editor of the New York Times, Greenwald acknowledges that ‘establishment media venues’ have done some ‘superb reporting’ in recent decades. But he argues that the default model in US journalism – that the reporter sets aside his subjective opinions in the interests of a higher truth – has led to some ‘atrocious journalism’ and toxic habits. These include too much deference to the US government of the day, and falsely equating a view that is true with one that isn’t, in the interests of ‘balance’.

The idea that journalists can have no opinions is ‘mythical’, Greenwald says. He reserves special contempt for one particular class: journalists who in his view act as White House stooges. He calls them sleazeballs. He asserts that instead of taking the powerful to task, the DC press corps frequently perform the role of courtier.

Keller, meanwhile, along with other thoughtful editors, have their own critique of ‘advocacy journalism’. Keller says: ‘The thing is, once you have publicly declared your “subjective assumptions and political values”, it’s human nature to want to defend them, and it becomes tempting to minimise facts, or frame the argument, in ways that support your declared viewpoint.’

In the months to come, Greenwald’s own brand of advocacy journalism was going to be subjected to more public scrutiny than he could ever have imagined.

In December 2012, one of Greenwald’s readers pinged him an email. The email didn’t stand out; he gets dozens of similar ones every day. The sender didn’t identify himself. He (or it could have been a she) wrote: ‘I have some stuff you might be interested in.’

‘He was very vague,’ Greenwald recalls.

This mystery correspondent had an unusual request: he asked Greenwald to install PGP encryption software on to his laptop. Once up and running, it allows two parties to carry out an encrypted online chat. If used correctly, PGP guarantees privacy (the initials stand for ‘Pretty Good Privacy’); it prevents a man-in-the-middle attack by a third party. The source didn’t explain why this curious measure was needed.

Greenwald had no objections – he had been meaning for some time to set up a tool widely employed by investigative journalists, by WikiLeaks and by others suspicious of government snooping. But there were two problems. ‘I’m basically technically illiterate,’ he admits. Greenwald also had a lingering sense that the kind of person who insisted on encryption might turn out to be slightly crazy.

A few days later, his correspondent emailed again.

He asked: ‘Have you done it?’

Greenwald replied that he hadn’t. The journalist asked for more time. Several more days passed.

Another email arrived. It persisted: ‘Have you done it?’

Frustrated, Greenwald’s unknown correspondent now tried a different strategy. He made a private YouTube tutorial showing step by step how to download the correct encryption software – a ‘how to’ guide for dummies. This video had little in common with the Khan Academy: its author remained anonymous, an off-screen presence. It merely contained a set of instructions. ‘I saw a computer screen and graphics. I didn’t see any hands. He was very cautious,’ Greenwald says.

The freelance journalist watched. But – stretched by other demands – didn’t quite get round to following its strictures. He forgot about it. ‘I wanted to do it. I work a lot with hacker types,’ Greenwald says. But ultimately: ‘He didn’t do enough to get himself up my priority list.’

Five months later, during their encounter in Hong Kong, Greenwald realised his would-be source back in late 2012 had been none other than Edward Snowden. Snowden was among Greenwald’s community of readers. Liking Greenwald’s world view, his brio and his uncompromising approach to government, Snowden had reached out to him, but unsuccessfully. ‘Snowden told me: “I can’t believe you didn’t do it. It was like: ‘Hey, idiot!’ ”’

Snowden in Hawaii was thousands of miles away from Brazil. There was little prospect of a physical meeting. Online contact was essential. Yet Greenwald had been too distracted even to follow Snowden’s simple encryption guide. The whistleblower’s frustration must have been considerable. Greenwald says: ‘He must have been thinking: “I’m just about to take this enormous fucking risk, to throw my life away, get killed, do the biggest security leak ever, and he [Greenwald] can’t even be bothered to get an encryption code.”’

As a consequence of this PGP debacle, several weeks passed uselessly. Snowden seemed to have no safe route through to Greenwald. The columnist carried on unaware, penning polemics in his remote mountain home. Marauding jungle monkeys would often invade, picking fights with the dogs, sometimes pelting them with branches, or retreating into dense thickets of bamboo. At other times Greenwald rolled around with his animals; he says this is a welcome distraction from politics and the remorseless stream of Twitter.

At the end of January 2013, Snowden tried a different way to get to him. He sent an email to Laura Poitras. He was hoping to open an anonymous channel to the documentary film-maker, who was Greenwald’s friend and a close collaborator. Poitras was another leading critic of the US security state – and one of its more prominent victims.

For nearly a decade, Poitras had been working on a trilogy of feature-length films about America in the years following 9/11. The first, My Country, My Country (2006), was an acclaimed portrait of Iraq in the aftermath of US invasion, told through the story of a Sunni Iraqi doctor who stood as a candidate in the 2005 post-Saddam election. The film was intimate, moving, compelling and brave – a luminous piece of work, nominated in 2007 for an Academy Award.

Poitras’s next film, The Oath (2010), was shot in Yemen and Guantanamo Bay. It features two Yemenis swept up in President Bush’s war on terror. One, Salim Hamdan, was accused of being Osama bin Laden’s driver and detained in Guantanamo; the other, Hamdan’s brother-in-law, was a former bin Laden bodyguard. Through them, Poitras created a powerful and human-scale critique of the dark Bush–Cheney years.

The response from US officials was astounding. For six years, between 2006 and 2012, agents from the Department of Homeland Security detained Poitras each time she entered the US. This happened around 40 times, she says. On each occasion, the agents would interrogate her, confiscate laptops and mobile phones, and demand to know whom she had met. They would seize her camera and notebooks. Sometimes she was held for three or four hours. Nothing incriminating was ever discovered.

Once, in 2011, when she was stopped at John F Kennedy international airport in New York, she refused to answer questions about her work, citing the first amendment. The border agent told her: ‘If you don’t answer our questions, we’ll find our answers on your electronics.’

In response to this harassment, Poitras adopted new strategies. She became an expert in encryption. She learned how to protect her source material and sensitive information. She understood why, given the NSA’s pervasive spying capabilities, this was sometimes very important. She no longer travelled with electronic gear. Sensibly, Poitras decided to edit her next film from outside America. She moved temporarily to the German capital, Berlin.

In 2012, Poitras was working on the concluding part of the trilogy. Its theme this time was America, and the alarming rise of domestic surveillance. One of her interviewees was William Binney, an NSA whistleblower. Binney was a mathematician who had spent nearly 40 years at the agency, and helped automate its foreign eavesdropping. He left in 2001 and blew the whistle on domestic spying.

That summer Poitras made an ‘op-doc’ for the New York Times website: a short film that was part of her work-in-progress. In the accompanying Times article, Poitras described what it was like being an NSA ‘target’.

From afar, Snowden observed Poitras’s harsh treatment. He knew who she was and what she had been through. Asked later by the Times journalist Peter Maass why he had approached Greenwald and Poitras, rather than his own paper, Snowden replied: ‘After 9/11, many of the most important news outlets in America abdicated their role as a check to power – the journalistic responsibility to challenge the excesses of government – for fear of being seen as unpatriotic and punished in the market during a period of heightened nationalism. From a business perspective, this was the obvious strategy, but what benefited the institutions, ended up costing the public dearly. The major outlets are still only beginning to recover from this cold period.’

He continued: ‘Laura and Glenn are among the few who reported fearlessly on controversial topics throughout this period, even in the face of withering personal criticism, and resulted in Laura specifically becoming targeted… She had demonstrated the courage, personal experience and skill needed to handle what is probably the most dangerous assignment any journalist can be given – reporting on the secret misdeeds of the most powerful government in the world – making her an obvious choice.’

In Berlin, Poitras brooded over the email that now came in from Snowden: ‘I am a senior member of the intelligence community. This won’t be a waste of your time…’ (The claim was something of an exaggeration. Not in terms of Snowden’s access to secret material but job title – he was a relatively junior infrastructure analyst.) Snowden asked for her encryption key. She gave it. She took other steps to assure Snowden, then still an anonymous source, that she understood how to communicate securely. ‘I felt pretty intrigued pretty quickly,’ she says. ‘At that point my thought was either it’s legit or it’s entrapment. There were two sides of my brain. One was holy shit, it feels kind of legit.’

Poitras wrote: ‘I don’t know if you are legit, crazy or trying to entrap me.’

Snowden replied: ‘I’m not going to ask you anything. I’m just going to tell you things.’

Poitras asked if Snowden had seen her file, detailing her detentions entering the US. He said he hadn’t. But he did explain that he had ‘selected’ her because of the harassment she had experienced. The security agencies had the capacity to track and monitor ‘anyone’, not just Poitras – across borders, city or streets, he said. ‘I bet you don’t like this system. Only you can tell this story.’

If anything, Poitras was even more paranoid than Snowden during this early period. She remained suspicious of an opaque government plot against her. Meanwhile, in Hawaii, Snowden was taking extreme precautions. He never made contact from home or office. ‘He made it clear it was hard for him to communicate. He was going to another location to do so. He wasn’t doing it from his regular networks. He created some kind of a cover,’ Poitras says.

The emails continued to flow. There was one a week. They usually arrived at weekends, when Snowden was able to slip off. The tone was serious, though there were moments of humour. At one point Snowden advised Poitras to put her mobile in the freezer. ‘He’s an amazing writer. His emails were good. Everything I got read like a thriller,’ she recalls. Snowden was keen to keep up a regular correspondence but clearly found it difficult to find a secure spot to type. He gave little away. There were no personal details.

Then Snowden delivered a bombshell. He said he had got hold of Presidential Policy Directive 20, a top-secret 18-page document issued in October 2012. It said that Obama had secretly ordered his senior national security and intelligence officials to draw up a list of potential overseas targets for US cyber-attacks. Not defence, but attacks. The agency was tapping fibre-optic cables, intercepting telephony landing points and bugging on a global scale, he said. He could prove all of it. ‘I almost fainted,’ Poitras says.

At this point the film-maker sought out trusted contacts who might help her authenticate these claims. In New York she consulted the American Civil Liberties Union, the ACLU. Over dinner in the West Village she talked with the Washington Post’s Barton Gellman. Gellman, a national security expert, thought the source sounded real. But he was a tad noncommittal. Meanwhile, the source made it clear he wanted Greenwald on board.

Back in Germany, Poitras moved ultra-cautiously. It was a fair assumption that the US embassy in Berlin had her under some form of surveillance. In connection with her latest documentary, Poitras had been in touch with Julian Assange, Washington’s bête noire, who since the summer of 2012 had been holed up in London’s Ecuadorean embassy. Given the company she’d been keeping and the many other reasons she was a person of interest to US security forces, she could be sure that any conventional means of communication would be monitored. Phones were no good; email was insecure. How could she contact her friend Greenwald about her mysterious correspondent?

It would have to be a personal meeting. In late March she returned to the States. From here she sent Greenwald a message, suggesting that they meet face to face, without any electronics.

Greenwald was already due to fly to New York to give a talk to the Council on American Islamic Relations (CAIR), the Muslim civil rights organisation. The pair met in the lobby of Greenwald’s hotel, the Marriott in Yonkers – an unlikely, ‘horrible’ venue for what was to be the first step of the most significant leak in US intelligence history.

Poitras showed Greenwald two emails. She didn’t know the unknown source had already tried to reach Greenwald himself. Was he real? Or an imposter, trying to entrap her? Poitras was excited, nervous and seeking verification. ‘There were no details in the emails. The source didn’t identify himself. He didn’t say where he worked,’ Greenwald says.

Instead of facts, the emails offered up a radical personal manifesto – an intellectual blueprint for why Snowden was prepared to leak classified material, and what the life-changing consequences of this action would inevitably be. ‘It was philosophically what he wanted to achieve and why he was willing to take these risks,’ Greenwald says. The source seemed credible: ‘Somehow Laura and I instinctively felt there was so much authentic passion about it. We both realised the emails were real. [The tone] was smart and sophisticated, not rambling or crazy.’

A picture was forming – of an intelligent, politically savvy, rational individual, of someone who had been working on a plan for some time. The source was unfolding it, stage by stage. The journalists had to wait for each new episode. ‘He was talking as though he was taking a huge risk, about disclosures that were very serious,’ Greenwald says. ‘He didn’t seem frivolous or delusional.’

Chatting to Poitras, Greenwald sketched out a way forward of his own. For the story to have impact, people needed to care, Greenwald argued. They would only care if the source could demonstrate convincing evidence of illegality – of wrong behaviour by the NSA, which went way beyond any democratic mandate. The best way of doing this would be to get hold of the national security documents: without them it would be difficult to rattle the doors on these issues.

The source behaved in an unexpected way. Poitras had assumed that he would seek to remain anonymous. After all, coming forward would bring the law down on his head. But Snowden told her: ‘I’m not cleaning the metadata. I hope you will paint a target on my back and tell the world I did this on my own.’

In another email Snowden said that the ‘hard part’ of pulling the documents was over, but that a different dangerous phase was beginning. ‘I could sense the stakes,’ says Poitras. ‘He was very worried about his friends and family being implicated. He didn’t want to remain anonymous. He didn’t want other people to take the fall.’

Snowden, it seemed, knew his actions were likely to end with him going to jail. He warned: ‘You need to manage your expectations. At a certain point I’m not going to be reachable.’

Once a relationship of trust had been established, Poitras told the source she would like to interview him. She told Snowden he needed to articulate ‘why’ he was taking these risks. This was important.

It hadn’t occurred to Snowden to give an interview. But the idea was a good one: his goal was to get the documents out to the world. He had had a view to leaking this material for four years, he said. At one stage he had considered giving the material to Assange. Eventually he rejected the idea. WikiLeaks’ submission site was down and Assange was under surveillance, stuck in a foreign embassy. Even with Assange’s security skills, Snowden realised it would be difficult to punch through to him.

By late spring 2013, the idea of a conclusive meeting was in the air.

‘I need six to eight weeks to get ready to do this,’ Snowden wrote.

What exactly the ‘this’ meant was still tantalisingly unclear. Poitras returned to Berlin. Greenwald returned to Rio. He got on with his life. The shadowy source was interesting. But – as is so often the case with journalistic leads – the ‘this’ could have been less alluring than it seemed; one of journalism’s many false starts. ‘I didn’t sit around fantasising about it. He could be fake,’ Greenwald says. As the weeks went by it seemed less rather than more likely that something would happen. ‘I gave it almost no thought. I really wasn’t focused on it at all.’

In mid-April, Greenwald received an email from Poitras. It told him to expect a FedEx delivery. Neither of the two parties had communicated much in the interim; Greenwald still hadn’t got encryption. But the FedEx parcel signalled that things were moving and that, as Greenwald puts it, ‘the eagle had landed’.

The package arrived; inside it were two thumb drives. Greenwald at first imagined that the USB sticks contained top-secret documents ‘wrapped in layers of encryption and Linux programs’. In fact, they contained a security kit, allowing Greenwald to install a basic encrypted chat program.

Snowden contacted Poitras again: ‘You should come. I will meet with you. But it’s risky.’

It was the next stage of their plan. Snowden intended to leak one actual document. The file would reveal collaboration between the NSA and giant internet corporations under a secret program called PRISM. ‘Heart attacks will be had over this,’ Snowden claimed.

Snowden didn’t want Poitras directly involved; instead he asked her to recommend other journalists who might publish it without attribution to him. He wanted to spread his net wider.

Poitras flew across to NYC again for what she imagined would be her meeting with a senior intelligence bureaucrat. She assumed this would naturally take place somewhere on the US east coast – probably in Baltimore, or a country house in Maryland. She asked for a minimum of half a day to film, and ideally a whole day. The source then sent her an encrypted file. In it was the PRISM PowerPoint. And a second document. It came as a total surprise: ‘Your destination is Hong Kong.’

The next day a further message arrived for Poitras, in which the source for the first time gave his name: ‘Edward Snowden’.

The name meant nothing; Poitras knew that if she searched Snowden’s name on Google this would immediately alert the NSA. Attached was a map, a set of protocols for how they would meet, and a message: ‘This is who I am. This is what they will say about me. This is the information I have.’

Snowden now contacted Greenwald himself, using his new encrypted channel. ‘I have been working with a friend of yours… We need to talk, urgently.’

The whistleblower finally had something he had been craving for nearly six months – a direct, secure connection to the elusive writer. The source was evidently familiar with Greenwald’s work. The two messaged. Snowden wrote: ‘Can you come to Hong Kong?’

The demand struck Greenwald as bizarre and it left him ‘really confused’: what would someone who worked for a US security agency be doing in a former British colony, part of communist China and far away from Fort Meade? ‘I didn’t understand what Hong Kong had to do with this,’ Greenwald says. His instinct was to do nothing. He was working on things that appeared important at the time; a book deadline loomed. ‘I kind of stalled a little bit,’ he says.

Snowden tried again via Poitras, urging her to get Greenwald to fly to Hong Kong ‘right now’.

Sitting alone in his Chinese hotel room, expecting exposure at any moment, Snowden was growing frantic. His plan to escape with a cache of top-secret NSA and GCHQ material had worked thus far with remarkable ease. That was supposed to be the hard part. But the easy bit – passing the material to sympathetic journalists – was proving tricky.

Greenwald contacted Snowden via chat. ‘I would like some more substantial idea why I’m going and why this is worthwhile for me?’

Over the next two hours Snowden explained to Greenwald how he could boot up the Tails system, one of the securest forms of communication, which uses the anonymising Tor network. Eventually the task was done.

Snowden then wrote, with what can only be called bathos: ‘I’m going to send you a few documents.’

Snowden’s welcome package was around 20 documents from the NSA’s inner sanctuaries, most stamped ‘top secret’. Among them were the PRISM slides. There were files that filled in the gaps on STELLAR WIND, the main case study of top-level impunity in Greenwald’s latest book.

It was, quite simply, treasure – a rich trove of extraordinary data. At a glance it suggested the NSA had misled Congress about the nature of its domestic spying activities, and quite possibly lied to it. Greenwald: ‘I always equate things with dog behaviour. Snowden was treating me like a dog and putting a biscuit in front of my nose. He was showing me top-secret programs from the NSA. It was unbelievable. There are no leaks from the NSA. It was enough to make me hyperventilate.’

Snowden was smart enough to indicate this was just the start – and that he was in possession of a very large number of secrets. Greenwald now comprehended. He picked up the phone to Janine Gibson, the Guardian US’s editor in New York. He said it was urgent. When Greenwald began explaining about the NSA documents, Gibson shut him down and said: ‘I don’t think we should be discussing this on the telephone.’ She suggested he come to New York.

Two days later, on Friday 31 May, Greenwald flew from Rio’s Galeão international airport to JFK, going directly to Guardian US’s SoHo HQ. He sat in Gibson’s office. He said a trip onwards to Hong Kong would enable the Guardian to find out about the mysterious source.

The source could help interpret the leaked documents. Many of them were technical – referring to programs, interception techniques, methods, that practically nobody outside the NSA knew existed. Most were not written in human language but in a kind of weird lexicon understandable only to the initiated. A few made no sense at all, as comprehensible as ancient Assyrian tablets.

‘This was a very serious thing. And the most exciting thing it was possible to imagine,’ Greenwald says. ‘Snowden had picked documents that got me completely excited. They worked with everyone at the Guardian. Some were mind-blowing. What we had was the tiniest tip of the iceberg.’

Stuart Millar, the deputy editor of Guardian US, joined the discussion. Both executives felt that Snowden’s manifesto came across as overwrought. In portentous terms, the source was talking about his personal philosophy, and the cataclysmic no-way-back journey he was taking. With hindsight, Snowden’s tone was understandable: he was, after all, about to become the world’s most wanted man.

But for the Guardian’s editorial staff there was a realisation that they could be in for a difficult ride – about to incur the wrath of the NSA, the FBI, the CIA, the White House, the State Department, and probably many other government departments so secret they didn’t officially exist.

Gibson and Millar agreed that the only way to establish the source’s credentials was to meet him in person. Greenwald would take the 16-hour flight to Hong Kong the next day. Independently, Poitras was coming along, too. But Gibson ordered a third member on to the team, the Guardian’s veteran Washington correspondent Ewen MacAskill. MacAskill, a 61-year-old Scot and political reporter, was experienced and professional. He was calm. He was unfailingly modest. Everybody liked him.

Except Poitras. She was exceedingly upset. As Poitras saw it, an extra person might freak out the source, who was already on edge. MacAskill’s presence might alienate him and even blow up the entire operation. ‘She was insistent that this would not happen,’ Greenwald says. ‘She completely flipped out.’ Greenwald tried to mediate, without success. On the eve of the trip, Poitras and Greenwald rowed for the first time ever. Tensions were high. At this point Greenwald was thinking of MacAskill as the Guardian’s corporate representative – as the cautious, dull guy. Later he discovered the Scot was the most radical of the three, prepared to publish much that was in the public interest.

At JFK airport, the ill-matched trio boarded a Cathay Pacific flight. Poitras sat at the back of the plane. She was funding her own trip. Greenwald and MacAskill, their bills picked up by the Guardian, were further up in Premium Economy. ‘I hate coach!’ Greenwald says, pointing out that he had slept little since arriving from Brazil 48 hours earlier.

As flight CX831 gained speed down the runway and took off, there was a feeling of liberation. Up in the air there is no internet – or at least there was not in June 2013. It was a space that, at that date, even the omnipotent NSA didn’t penetrate. Once the seatbelt signs were off, Poitras joined Greenwald in Premium Economy: there was room in front of his seat. She brought a present they were both eager to open: a USB stick. Snowden had securely delivered to her a second cache of secret NSA documents. This latest data-set was far bigger than the initial ‘welcome pack’. It contained 3–4,000 items.

For the rest of the journey Greenwald read the latest cache. Sleep was impossible. He was mesmerised: ‘I didn’t take my eyes off the screen for a second. The adrenaline was so extreme.’ From time to time, while the other passengers slumbered, Poitras would come up from her seat in the rear and grin at Greenwald. ‘We would just cackle and giggle like we were schoolchildren. We were screaming, and hugging and dancing with each other up and down,’ he says. ‘I was encouraging her loudness.’ Their celebrations woke some of their neighbours up; they didn’t care.

It had started as a gamble. But now the material was becoming a scoop to end all scoops. What Snowden revealed was looking more and more like a curtain dramatically pulled away to reveal the true nature of things. As the plane came in to land, the crowded lights of Hong Kong twinkling below, there was for the first time a sense of certainty. Greenwald had no more doubts. Snowden was real. His information was real. Everything was real.