Scott Z. Burns has been mostly known as a screenwriter on such Steven Soderbergh projects as “The Informant!” (2009), “Contagion” (2011) and “Side Effects” (2013). Here, in this dark delve into recent U.S. misdeeds, Burns not only writes but takes the director’s chair, with Soderbergh as producer. The simplistic title “The Report” represents something more complex and foreboding – “The Torture Report,” with that middle word crossed off as soon as it spills across the screen in the opening credits. The report in question concerns waterboarding and other “enhanced interrogation techniques” employed by the Bush administration in the wake of 9/11, and is deeply redacted by the CIA.

If you haven’t seen “Zero Dark Thirty” (2012), Kathryn Bigelow’s brilliant take on the hunt for Osama bin Laden, there’s a scene early on demonstrating the use of the interrogation techniques. It’s throughly unpleasant, and“The Report” dials the discomfort up from a 9 to, say, an 11. The film begins with U.S. Senate aide and researcher Dan Jones (Adam Driver) consulting with a lawyer about possibly treasonous charges against him for “relocating” a CIA document, then winds back to when Jones, who toiled in counterintelligence after college, lands on the staff of U.S. Sen. Dianne Feinstein and is tasked to lead a U.S. Senate Intelligence Committee probe into the CIA’s use of torture after 9/11.

It’s mostly a paper trail chase, but a riveting one – think “All the President’s Men” (1976) replete with a mini-me version of Deep Throat. Jones and his team are granted access to documents in a secure basement vault on CIA turf, but no documents are to leave the chamber, and Jones and associates aren’t allowed to interview any of the operatives involved. Meanwhile Feinstein (Annette Bening), solemn and serious, applies pressure to agency leaders under the Bush and Obama regimes, finding the desire for it all to go away is clearly bipartisan.

Through documents (which lead to dramatizations of events) we learn of contractors James Mitchell (Douglas Hodge) and Bruce Jessen (T. Ryder Smith), slithering sorts and former military intel who sell a fictitious (or composite) CIA honcho named Bernadette (Maura Tierney) on enhanced interrogation even without proven results. From the PowerPoint presentation alone, viewers’ eyebrows will raise, but for Bernadette it’s a key weapon in the war on terrorism – Geneva Conventions be damned. As a pair, Mitchell and Jessen are something of a disturbing chuckle, lapping up taxpayer-bought scotch aboard jets and going about their business like Kidd and Wint in the Bond flick “Diamonds are Forever” (1971). Through it all Tierney’s dutiful top cop promises results to her higher-ups and sits and watches the heinous shenanigans (naked men being beaten and sleep deprived by heavy metal music played at eardrum-bursting levels) with cold steely resolve, forever waiting.

The definition of “torture,” as explained in the film, is complicated: It turns out that if you can extract information that can save lives, how you got it doesn’t matter; if not, enhanced interrogation is a human rights violation, and you’ll be left out to dry. Burns orchestrates some nice juxtapositions in setting: Most of the film takes place in dark, windowless rooms, be it that basement vault where Jones and crew toil away in, the subterranean hellholes on foreign soil where Mitchell and Jessen perform their dirty deeds or the soulless conference room on Capital Hill that serves as a boxing ring for Feinstein and CIA Director John Brennan (Ted Levine).

From top to bottom, the performances impress. Bening shines as the fiery Feinstein demanding accountability, and Linda Powell brings similar intensity as loyal Feinstein staffer Marcy Morris; John Hamm adds rational cool as Denis McDonough, the Obama chief of staff trying to hold the middle ground. Of course, the film hangs from Driver’s dogged research wonk, whose focus and commitment to the task and idealism is imbued with a heaviness and signs of fraying over the long-fought years. Words matter – in this case, a very specific one.