Crammed with information and moving at a breathless pace, Bill Condon’s docu-drama about the rise of the whistleblower website WikiLeaks and its driven founder Julian Assange is as fascinating as its protagonist, but just about as flawed. Neither pure hagiography nor simple hatchet-job, “The Fifth Estate” proves a fairly judicious account of a radical new movement in underground journalism that, despite all its technical bells and whistles, turns out to be curiously old-fashioned and conventional in narrative terms.

Tall, rangy Benedict Cumberbatch cuts an appropriately strange figure as the mercurial Assange, conveying his peculiar combination of principle and egomania. Josh Singer’s script tosses in a few allusions to the character’s upbringing in Australia—flashbacks to his childhood in a commune and his early forays in hacking—but the focus is on his efforts to raise the profile of an operation still in its infancy by releasing information sure to provoke reaction at the highest levels of power. That means not just material revealing corruption in African governments, malfeasance at European investment banks or financial misconduct among the political powers in Iceland, but a storehouse of documents proving lies and cover-ups within the American government concerning the conduct of military operations in Iraq and Afghanistan and duplicity in diplomatic relations with other countries.

Ever suspicious of sharing the sources he guards so closely, Assange nonetheless takes young German computer expert Daniel Berg (Daniel Bruehl) into what turns out to be his very small circle, and together they expand the site’s capabilities (enlisting Berg’s friend Marcus, a hacking genius played by Moritz Bleibtrau, and Icelandic activist Birgitta Jonsdottir, played by Carice van Houten, in the operation) while arranging the simultaneous publication of the evidence Assange has amassed on U.S. malfeasance in old-line media outlets—The Guardian in Britain, the New York Times in America, and Der Spiegel in Germany. It’s the conflict between Assange’s headlong rush to release the material without careful redaction and the insistence of his more traditional partners—people like Nick Davies and Alan Rusbridger, the investigative reporter and managing editor of the Guardian, played respectively by David Thewlis and Peter Capaldi—that great care be taken to minimize danger to innocent parties that leads the WikiLeaks founder to become increasingly erratic and paranoid. He even comes to view the faithful Berg as a turncoat, although the German has been so doggedly devoted to Assange that it strained his relationship with his girlfriend Anke (Alicia Vikander). This plot strand of “The Fifth Estate” can be described as a sort of nerd bromance gone bad.

Singer and Condon also take time to dramatize the impact of the revelations Assange is stage-managing back in Washington through the desperate efforts of State Department officials James Boswell (Stanley Tucci) and Sarah Shaw (Laura Linney) and White House spokesman Sam Coulson (Anthony Mackie) to minimize the damage. Their scenes are amusing mixtures of serious issue discussion and cynical observation, but they’re all invented, of course. (Given that, it might have been a good jest to rename Linney’s character Sam Johnson to accompany Tucci’s Boswell.) Washington’s furious reaction fuels Assange’s certainty that he’s being targeted by dark forces—a feeling that was not entirely unwarranted, but which fed his increasingly unhinged behavior.

Singer’s treatment lays all of this out with a reasonable degree of clarity, though it would be beneficial for a viewer to have watched Alex Gibney’s far more straightforward documentary, “We Steal Secrets: The Story of WikiLeaks,” beforehand to make it more intelligible. (Another nice complement would be Ken Auletta’s first-rate profile of Rusbridger in a recent issue of The New Yorker, which depicts a man devoted to a more measured, circumspect but still courageous form of investigative journalism.) But Condon, in concert with cinematographer Tobias Schliessler and editor Virginia Katz, rather muddies the clarity with a take-no-prisoners visual style, which begins with a frenetic news-delivery-systems-through-history montage under the opening credits and runs through cascades of images filled with encrypted text, split screens and wild camera swings as the narrative proceeds, almost always accompanied by Carter Burwell’s badgering core. The general melee helps to explain why the quieter, more subdued moments—like the genial scenes between Linney and Tucci, or an oddly moving sequence in which Berg takes Assange to dinner at his parents’ house, only to have the Australian proves a distinctly contemptuous guest—come as such a relief. (You have to wonder whether the experience of directing the two “Breaking Dawn” films hasn’t had an unfortunate effect on Condon, who once embraced a chastely classical approach in films like “Gods and Monsters” and “Kinsey.”)

Still there’s much to admire here, most notably Cumberbatch’s oversized portrayal as Assange. It’s true that the actor isn’t able to penetrate very deeply into the character, but he does at least suggest the uberleaker’s charismatic power as well as his unsavory side. Bruehl, another fine actor, isn’t nearly as fortunate; Berg is frankly a rather dull, straitlaced figure, and he script does little to elevate him beyond the role of the faithful sidekick who eventually realizes he’s been badly used. Like Bruehl, the rest of the cast basically provide little more than slightly aghast reactions to the maelstrom that Assange—and Cumberbatch—suck them into.

“The Fifth Estate” deserves respect, even admiration, for tackling a controversial contemporary subject head-on and suggesting the promise, and perils, of the sort of Internet activism WikiLeaks represents. If Condon’s achievement doesn’t equal his ambition, at least it tries to do something serious, which is more than can be said of most Hollywood movies today. And the fact that those on both sides—Assange’s most vocal supporters and his most vitriolic detractors—are likely to be displeased by it is certainly a point in its favor.