It began with a 2015 email from out of the blue to a reporter, Bastian Obermayer, with a newspaper in Munich, Germany.

The author, labeling her or himself “John Doe,” was “just a concerned citizen” seeing ” unbelievable amount of corruption” at this Panamanian law firm and promising a data dump to ensure this got “exposed” and reported.

It was the “world, hidden from most of us” detailing how “French Revolution level income inequality” was being perpetrated by the super rich preying on governments and “We the people” who make up those governments.

It became “the largest leak of secret documents in history,” millions of emails and PDFs detailing offshore tax avoidance, money laundering and criminality ranging from stashing cash for drug kingpins to tax dodging to the money laundering “investments” that get hotels built for a certain future American president.

Dummy corporations and shell companies attached to Syria’s dictator Assad, Saudi sheiks, President Sharif of Pakistan, Prime Minister Gunnlaugsson of Iceland, Putin and Trump, Lionel Messi and the FIFA officials who govern his sport were exposed.

“The Panama Papers,” as they were called, became a scandal unlike any other, global in scale, “revealing a hidden world” where human civilization’s wealthiest codified global income inequality through outright criminal acts, and colluding with other criminals.

Alex Winter’s documentary “The Panama Papers” tells the story of “How we got that story,” names names and gets into the fallout from this story, which wasn’t the easiest to sell to a planet that’s come to see “kleptocracy” as “the new normal.”

Leaders were impeached or resigned, others stonewalled or refused to release their tax returns, and reporters died — killed by the powerful and shady figures (and public ones) whom this story hurled into the spotlight.

The wealthy of 200 countries were tied, via some 11.5 million documents shared by this one anonymous “John Doe,” to the Panamanian law firm Mossack Fonseca, since closed, its leader imprisoned. It was a firm married to the mob and mobsters, where “their business was secrets,” a business supposedly incorruptible politicians (David Cameron) felt the need to hire to avoid taxes and launder investments from underworld figures (Donald J. Trump).

The original reporter, Obermayer, started to realize “Maybe it’s not a good idea that only I know.” When you’re reporting on the corruption of murderous Russians and Saudis, of South American drug lords, there’s safety in numbers. He and his newspaper drew in American news organizations, The Guardian newspaper in Britain and papers and reporters in most every country which had famous names locked in that cache of data — Malta and Spain, Iceland and Panama.

Winter, who has used his post “Bill and Ted’s Excellent Adventure” years to become a good documentary filmmaker and a sharp interviewer, built his movie on interviews with the reporters, lengthy quotes from “John Doe’s Manifesto,” the whistleblower’s reason for leaking the data (Elijah Wood reads that manifesto in voice-over), graphics and clips from the movie “Scarface,” which touched on how widespread money laundering — the practice of taking illegally-obtained drug or human trafficking, murder for hire, etc. cash, and getting it “cleaned” by pouring it, along with bribes, into allegedly legitimate businesses — is.

One good example, the ways Donald Trump finances hotels with his name on them. Here’s proof that one in Panama used money from unsavory underworld figures to finance and build it, the details of how Trump creates such deals with crooks the world over. The crooks overpay for those investments, and Team Trump gets to skim from that.

We see political leaders confronted and chased from office in some countries (Iceland, Britain, Brazil), hear about Leticia Montoya, a poor secretary with the law firm, who serves on the boards of 10000 paper corporations — not benefiting from this big con one cent herself.

Winter, heard asking smart, pointed questions off camera, celebrates the heroic journalists involved in this story, getting them to give mini-autobiographies before they show and tell how they, and the International Consortium of Investigative Journalists, went through the papers and found the dirt that shook the world.

A couple of folks from McClatchy News Service, which I used to work for, talk about how hard it was to “sell this story to our company. Reporter Kevin Hall notes, “Who’s surprised that bad guys hide their money?”

Marissa Taylor, one of over 100 journalists worldwide involved in the expose, adds “Why are people going to care that the rich don’t pay their taxes and crooks are crooks?”

But they told the story anyway, and in much of the world, heads rolled and continue to roll. In America, we elected a kleptocrat president.

“This story revealed a whole hidden world. This was…the goods,” Taylor says.

Most disturbing of all are the investigative journalists who use the phrase, “state capture” in describing countries where vandal capitalism has put the crooks in charge. Malta, Iceland and Brazil are named, and then U.S. Treasury Secretary Steve Mnuchin’s sham of a confirmation hearing is repeated, his dodging of questions about sham corporations and tax avoidance and worse (Trump campaign manager Paul Manafort is juxtapositioned with Mnuchin) suggesting that this has happened in the United States as well.

With Senate Majority Leader Mitch McConnell, married into a Chinese oligarch family, covering the vast array of crimes and criminal appointments up, we are looking at “Trump cozying of to his fellow kleptocrats as a way of making this the new normal,” former Senate ethics lawyer and tax law specialist Jack Blum declares.

It’s all pretty distressing, and the fact that so many other scandals have chased this epic one off the front pages just adds to to helplessness such exposes cannot help but create. Winter has made an important film, but an exhausting and dispiriting one about a scandal 99% of the world should care about.

While American journalists haven’t been killed (save for one the Saudis murdered in Turkey), you really wonder if we will ever see a story like this brought to light again, and if the world’s embattled news organizations will ever have the resources to stay with this until “justice is done, though the heavens may fall.”

MPAA Rating: unrated

Cast: Luke Harding, Frederik Obermaier, Bastian Obermayer, voiceover by Elijah Wood

Credits: Written and directed by Alex Winter. An Epix release.

Running time: 1:40