What is now the Panama Papers - the world's largest leak of private documents - started in 2014 as a tantalising exchange on an encrypted chat messaging service between an anonymous source and journalist Bastian Obermayer of Munich- based daily Suddeutsche Zeitung.
Source: "Hello, this is John Doe. Interested in data?"
Mr Obermayer: "We're very interested."
Source: "There are a couple of conditions. My life is in danger. We will only chat over encrypted files. No meeting, ever."
Mr Obermayer: "Why are you doing this?"
You need to park your ego when you work for us. We are sensitive about avoiding conflicts and rivalries.
MR GERARD RYLE, International Consortium of Investigative Journalists director
Source: "I want to make these crimes public."
Mr Obermayer: "How much data are we talking about?"
Source: "More than anything you have ever seen."
In the months that followed, John Doe transferred some 2.6 terabytes of data. The cache of 11.5 million documents from Panamian law firm Mossack Fonseca has since implicated the world's rich and powerful, revealing how they or those close to them hide their wealth offshore. Offshore entities of themselves are, however, not illegal.
After seeing just a portion of the leaked documents, the German daily sought help from the Washington-based International Consortium of Investigative Journalists (ICIJ). The ICIJ previously published secret internal records of offshore firms in the British Virgin Islands.
An ICIJ team went to Germany to work with the newspaper and started the complicated task of coordinating an effort that eventually involved over 400 journalists and 100 publications around the world.
The consortium, started 18 years ago as part of the Washington- based Centre for Public Integrity, has its own full-time team as well as 190 members worldwide.
According to non-profit journalism institute Poynter, individual journalists looking to join the ICIJ submit resumes and clips and are vetted before being admitted. Members can then opt in to ICIJ projects that interest them.
The consortium stresses collaborative work. "You need to park your ego when you work for us," ICIJ director Gerard Ryle told Poynter. "We are sensitive about avoiding conflicts and rivalries."
The ICIJ's leadership includes a number of Asian media figures like the founder of Indonesia's Tempo magazine Goenawan Mohamad and former South China Morning Post editor-in-chief Reginald Chua.
Much like Wikileaks - the notorious organisation that released 1.7 gigabytes of confidential diplomatic cables in 2010 - ICIJ works mostly with huge data files.
It also tends to focus on stories with an international impact rather than those simply involving the United States. Previous projects include reports on members of the Chinese elite parking funds in New York real estate, on how much money companies that donated to US president George W. Bush gained in war contracts in Iraq and Afghanistan, and on how Luxembourg operates as a tax haven. That made the ICIJ perhaps uniquely qualified to deal with the Panama Papers - a stockpile some 2,000 times bigger than the Wikileaks cache in 2010.
Much of the story of what happened from the time of the first contact between John Doe and Suddeutsche Zeitung to the revelations published in newspapers across the globe sounds like a modern-day Deep Throat.
Deep Throat is the nickname for the source behind the information that ultimately forced US president Richard Nixon to resign in 1974 over the Watergate scandal.
Where Deep Throat and the journalist relied on flower pots and marked newspapers to communicate clandestinely, Mr Obermayer and John Doe kept in contact through highly encrypted chat messaging apps and e-mail. And even then, they established some code words to start exchanges to ensure neither side had been compromised.
"I'd say 'Is it sunny?' You'd say 'the moon is raining' or whatever nonsense, and then both of us can verify it's still the other person on the device," Mr Obermayer told Wired magazine.
He did not want to reveal the specific apps used or how such a huge amount of data was transmitted.
A lot of the hard work of making the data manageable was done by the ICIJ. It built a search engine, called Blacklight, for the data sent and also set up a secure social media site with a live chat function for reporters to exchange tips.
"Within the first few months, people were really realising, 'Hey, there's a lot of really important stuff,' " ICIJ senior editor Michael Hudson told Time magazine. "The sheer size of the data, the fact that we had world leaders in the data - it was clear this was important."
The ICIJ shared the site with dozens of news organisations around the world. Reporters on the ground then hunted down leads on the names they found in the database.
In the end, more than 120 names of public figures and politicians were implicated, with the possibility of more to come.
Russian President Vladimir Putin and the family members of top Chinese leaders are said to have links to offshore companies. Iceland's Prime Minister Sigmundur David Gunnlaugsson quit last week, becoming the first political casualty.
There was surprisingly little mention of Americans in the data trove. Most experts here say Americans who want complicated offshore shell companies have a multitude of local firms to help them without having to look to Panama.
The ICIJ has said it does not intend to release the data trove en masse as much of it is "of no interest to the public". It does, however, intend to continue to mine the information and will release the names of some 214,000 offshore entities involved next month.