If filmmaker Alex Gibney was an oncologist, he’d be the one you could rely on if you asked, “Give it to me straight, doc. Is it the Big Casino?”

He makes films that have a dogged devotion to the unvarnished truth. Scientology to Steve Jobs, the “real” story of Enron or Lance Armstrong, Gibney’s reputation as a documentary truthteller is unimpeachable.

So if you want the hard answers about Russian manipulation of elections and whether Donald Trump was “cultivated” as a “Russian asset” who might win the White House and pander to Russia’s interests, Gibney’s the guy to go through the Russian nesting dolls to give us something like the unvarnished truth.

“Agents of Chaos,” the two-part film he directed for HBO (premiering Sept. 23), uses that nesting doll image and allegory, scores of interviews and reiterations of the reporting of what we knew in 2016, and what we now know, to lay out — in clear but somewhat exhaustive detail — how it all went down.

“Agents” traces Russia’s 2013-2014 Ukrainian practice-run “lab” of public opinion manipulation, sewing division and seeding “fake news” to the St. Petersburg troll farm IRA, names the known names of the hackers who fed Wikileaks and willing American media companies stolen documents and gossipy emails, digs into “collusion” and draws conclusions.

Several of the principals involved in all this — Russian “connections” such as Felix Sater and Carter Page, ex-CIA chief John Brennan, Fusion GPS chief Glenn Simpson and email hack victim John Podesta are here.

Gibney and others pick at the “Steele Dossier” and “Guccifer 2.0,” the manufactured “hero worship” of Julian Assange and “insidious” Wikileaks (Gibney did an earlier film on them), “Trump Tower Moscow” and other blind alleys a salacious press corps chased while the more blunt truth was practically right out in the open.

Years of Trump singing Putin’s praises on Fox News are sampled, Trump’s parroting of Russian positions on everything from the EU and NATO to the myth of “American exceptionalism” are revisited.

Trump “does things for (Russia) in public that they can’t do for themselves,” one insider explains.

We’re tipped that, in movie terms, the Russians were acting as if “they were in some John LeCarre (“Tinker, Tailor Soldier Spy/The Russia House”) spy movie” while Trump’s team were playing roles in a New York “mob movie.”

We see how the troll farm in St. Petersburg learned on the fly, made research trips to Red State America and figured out how easily it would be to create fake social media profiles and fake Texas “secessionist” groups like Hearts of Texas on Facebook, not just to create and disseminated divisive memes, but more importantly — to amplify the hate, mistrust and bigotry that was already out there.

From Alex Jones’ InfoWars to CNN, everybody seemed to fall for it.

Gibney takes pains to show both “what Russia did to us,” and “what we did to ourselves” in this process.

Journalists, academics (historians) provide big picture perspective and analysis of Putin’s motives, Trump’s eager compliance, “authoritarian” playbook moves (assaults on protestors, blizzards of bald-faced lies, a daily outrage) and the “profound form of failure” of the media to avoid chasing mirage and not the real story.

In a year when such films and books (Andrew Weissmann, part of the Mueller team who has a new book out, is here) are legion, “Agents of Chaos” stands out for synthesizing so much of what we’ve heard, what we’ve come to believe about Russia and Trump (some of it mistakenly) and what exactly is on the line in November. It’s wearing and exhausting to go over all this again. But that’s nothing, the film suggests, to how alarming we should be that millions of our fellow citizens don’t look at Russia today with revulsion and fear — that they and we and Trump are remaking our democracy in Russia’s corrupt, autocratic image.

Cast: Margarita Simonyan, Felix Sater, Glenn Simpson, Victoria Nuland, John Podesta, John Brennan, Camille Francois, Andrew McCabe, David Hinkton, Andrew Weissmann, Carter Page, Michael Isikoff

Credits: Directed by Alex Gibney and Javier Alberto Botero, created by Gibney and Lowell Bergman. An HBO release.

Running time: Two episodes @2:00 each