LONDON - David Leigh presses the entry button and walks into the room. He doesn't bother to punch numbers into the keypad of any sophisticated locking system, nor is he asked to show any sort of identification. There don't appear to be any surveillance cameras operating there either. He enters the room called "the bunker." In recent months, one of the largest and most important scoops in the history of journalism was compiled here: the exposure of U.S. State Department documents on the WikiLeaks website.

The room is located in the modern Kings Place building, not far from the busy Saint Pancras and King's Cross train stations in London. The editorial offices of the veteran British daily The Guardian moved there about a year ago. In the age of digital media, the Guardian, like most newspapers around the world today, is fighting for its existence. This struggle has been riding a tailwind in recent months, thanks to the publication of secret documents belonging to the U.S. Army and State Department obtained by WikiLeaks - which then shared them with a number of important newspapers.

"Welcome to the bunker," Leigh says to me, introducing his partner and colleague Luke Harding. Leigh, 65 and a veteran newsman, heads the paper's investigative desk. Harding, two decades his junior, was the Guardian's correspondent in Moscow - but since November he has been at the London headquarters, after being expelled from Russia. In December, Harding published documents from the big leak in which Russia is described as a "Mafia state." When he tried to go back there at the start of this month, he was refused; only last week was he given permission to return.

In the center of the room stand two tables holding six computers with large screens; the same computers which store the files of the leaked documents. Since last July, the two men have been sifting through hundreds of thousands of documents, many of which have been edited and published prominently in their newspaper. This month saw the publication of their collaborative book, "WikiLeaks: Inside Julian Assange's War on Secrecy," referring to the controversial founder of the whistleblower website.

The disgruntled private

The documents in question were leaked last year by Bradley Manning, a 23-year-old private who served in an intelligence unit of the U.S. Army in Iraq. After the fact, he said his motives were ideological and political, and that he wanted to tell the world the truth and expose his government's lies.

Manning was surprised to find that although the secret operations room in which he served as a computer expert was safeguarded by a five-digit entry code, anyone could knock on the door and come in. And so, at an intelligence base in the desert 50 kilometers from Baghdad, without planning ahead, he copied a quarter of a million secret documents onto a few personal discs, on which Lady Gaga songs had previously been burned.

Among other things, Manning copied a file containing documents and video from the war in Iraq; documents concerning the war in Afghanistan; and the main file, containing about a quarter of a million items of correspondence between American diplomats around the world and headquarters in Washington.

When he saw how Iraqi police officers were arresting and torturing innocent people, Manning says he complained to his commanding officer, who told him not to interfere in other people's business. At that stage, according to Manning, he decided to do something with the materials he had copied onto the CDs.

He was impressed by the WikiLeaks site, which was launched in 1999, and contacted its operator, Julian Assange - whom he defined as "a crazy white-haired Aussie who can't seem to stay in one country very long." After an exchange of suspicious messages, Assange and Manning found a common language. By means of encoded conference calls over the Internet, Manning sent Assange all the files he had stored on the discs.

In March of last year, Assange went to Norway to lecture at an international conference of investigative journalists. As is his habit, he was carelessly dressed, with his brown coat buttoned to his neck, his graying hair mussed and his hands never leaving his bag. In the bag he carried several laptop computers, cables, SIM cards and portable telephones.

The 3 A.M. meeting

Also attending that conference was Leigh; The Guardian and WikiLeaks had already worked together a year earlier after a court order from a London judge prevented the paper from publishing a comprehensive investigation of Barclays Bank's attempt to defraud the tax authorities. In response, The Guardian passed all the relevant documents in its possession to WikiLeaks, which then published them online.

At the conference, after his lecture and a lush meal, Assange turned to Leigh and asked him if he'd like to see something. At 3:00 in the morning, Assange arrived at Leigh's room, took one of his computers out of his bag, typed in a secret code and brought up a black and white video.

According to Leigh, the footage showed a shooting carried out by an American attack helicopter in 2007 against a group of civilians. Twelve people were killed in the attack, including children. One can hear in the video the pilot expressing scorn for human life and a light finger on the trigger. Assange hinted that that particular piece of footage was just the tip of the iceberg of a tremendous treasure trove of information in his possession. Leigh was unable to persuade Assange to let The Guardian publish the video; Assange did that himself two months later, on the WikiLeaks site.

The Guardian continued to track down the Australian, who continuously moved around from one country to another. Nick Davies, a chief investigator at The Guardian and one of its stars, chased Assange to Belgium, where last summer he succeeded in sitting him down for a six-hour marathon conversation in a hotel cafe. At the end of that exchange, Assange grabbed a coffee-stained hotel napkin and quickly scribbled down some numbers and letters.

"Here, it's yours," he said. This was the password to enter the website where the founder of WikiLeaks had stored the documents.

The two parties agreed that representatives of the American newspaper The New York Times and the German newspaper Der Spiegel would also be partners in the deal. Assange was interested in exposing the documents through a large and important U.S. news outlet; The Guardian also wanted this because it feared that if it was alone in the fight, the American government would apply to the British government for a gag order. Assange was also convinced by The Guardian's argument that Der Spiegel could help fund the exposure, as it has a lot of money. Assange and his site did not receive any payment from the newspapers for the leaked documents.

Last July, representatives of the three newspapers found themselves in "the bunker" in London. Assange had demanded that the Guardian staff treat the meeting as a secret intelligence operation, showing them how easy it was to hack into their e-mail. They promised to take security precautions when using telephones and to encode their computer communications, but their efforts were to no avail. Leigh says they tried to keep the existence of the bunker and their clandestine work secret - "But apparently," he laughs, "journalists don't really know how to do this."

Within a short time, quite a number of Guardian employees knew "something big" - an unprecedented journalistic scoop - was cooking in the secret room.

After several months of work in the bunker, the three newspapers finally published the documents. They were joined by Le Monde in France and El Pais in Spain. Among other things, they revealed that leaders of Arab countries supported a military solution against the Iranian nuclear program and they printed undiplomatic statements concerning world leaders made by many American ambassadors stationed in foreign capitals.

The documents concerning Tunisia also aroused a great deal of interest, as they revealed the corrupt government in all its nakedness. The revolution in that country has been described as "the first WikiLeaks revolution."

Most of the documents have not yet been revealed. In the meantime, the capricious and unpredictable Assange has fought with The New York Times over an unflattering portrait published of him, and he has also had a falling out with The Guardian for refusing to cut off its ties with the American newspaper. As revenge, Assange has also given some of the documents in his possession to The Guardian's conservative rival, The Daily Telegraph.

The arrest

Immediately after Assange published the footage from Baghdad, Manning became very tense and was on the verge of a nervous breakdown. He contacted Adrian Lamo, a famous American hacker who had been given a suspended sentence for breaking into the computers of The New York Times. Gradually, Manning acknowledged that he was responsible for leaking the material to Assange (incidentally, the two have never met face to face ). Lamo then turned Manning in to the U.S. Army authorities. Since then, the U.S. private has been held in a two-by-four meter cell at a prison in Virginia awaiting trial.

Assange, too, is awaiting trial. But the conditions of his arrest are far more comfortable. For the past two months he has been at Ellingham Hall, a country manor near Norfolk in East Anglia. A court released him on bail to house arrest there, after he was arrested in November under an order from the prosecution in Sweden, where he is suspected of rape. The hearing on his extradition will be held next week.

The estate were Assange is staying belongs to Vaughan Smith, a former officer in an elite battalion of the British Army who became a journalist after his demobilization and has documented wars in the Balkans, Iraq and Afghanistan. He also runs an organic farm on his property and when he tired of his journalistic work, he founded the Frontline Club in London for foreign correspondents, where he serves delicacies created from his organic crops.

A strange friendship developed between the leftist Assange and the British adventurer Smith who supports the Conservative Party. Assange and his six disciples - from Guatemala, Iceland and Britain - relocated their place of residence from the floor of the Frontline Club to Smith's estate.

Disillusioned defectors from Assange's group, among them Daniel Domscheit-Berg who had been defined as his German deputy, describe Assange as a domineering person who established a kind of cult. They also say he has had sexual relations with most of the women in the group. Ironically, Assange - who believes "everything is leakable" - requires everyone who works for the organization to sign a document forbidding them from releasing any information. Anyone who does so can expect to be sued.

Where is Julian?

After my meeting with people at The Guardian, I traveled to Ellingham Hall to ask Assange about two problematic points in his activity: his unfathomable connections with Iran and his relationship with a Holocaust-denying apostate Jew. He refused to meet with me. Sarah Harrison, his spokeswoman and girlfriend, did not reply to my queries either.

In November, Assange visited Geneva as a guest of the International Institute for Peace, Justice and Human Rights, delivering a lecture on their behalf. The Iranian government funds the activities of this institute. Assange has related proudly to people who have spoken with him that he only agreed to go to Geneva in return for 20,000 euros.

It seems that Assange has no moral inhibitions and that he is prepared to accept money from any source, just so he can fund WikiLeaks' activities. Guardian reporters were astonished to find that Assange appointed Israel Shamir, a Russian-Israeli anti-Semitic Holocaust denier, as his representative in Moscow and transferred about 2,000 euros to Shamir's bank account in Latvia. Leigh says they warned Assange not to pal around with such dubious characters, but adds that he doesn't listen to anyone, only to himself.

In his introduction to "WikiLeaks: Inside Julian Assange's War on Secrecy," The Guardian's editor Alan Rusbridger wrote that he resisted pressure from the U.S. administration and published the material. Of Assange he says, "From being a marginal figure invited to join panels at geek conferences he was suddenly America's public enemy number one. A new media messiah to some, he was a cyber-terrorist to others."

When American law enforcement authorities were unsuccessful in incriminating Mafia boss Al Capone, they locked him up for tax violations. Now it remains to be seen whether the United States will use a similar tack with Assange and see to his arrest not because he revealed its secrets, but thanks to a Swedish law that accuses him of rape for having sex without a condom while the woman was asleep.