IF THERE is one thing that “The Fifth Estate” makes clear, it is how fascinating and altogether stranger-than-fiction Julian Assange really is. Bill Condon’s kinetic drama about the rise and partial fall of WikiLeaks includes flashbacks to Mr Assange’s childhood in a brutal Australian cult. It touches upon his youthful hacking of NASA’s computers. And it reminds us of the messianic zeal with which he extols the revolutionary power of information-sharing. If any 21st-century public figure deserves a biopic, it is Mr Assange. It is frustrating, then, that “The Fifth Estate” is not that biopic. The film is adapted from two books, one of them a memoir written by Daniel Domscheit-Berg, Mr Assange’s Berlin-based sidekick during the early days of WikiLeaks. Mr Condon and his screenwriter, Josh Singer, stage the febrile events of 2007 to 2011 as they were perceived by Mr Domscheit-Berg (Daniel Bruhl), so Assange is rarely seen without Daniel’s company. It is an approach that makes sense as long as the two cyber-conspirators are together in squats and cafes, plotting to expose corruption and tyranny, or hurrying through airports with backpacks slung over their shoulders. But when Mr Assange is somewhere else, which he is for much of the running time, the film is no longer about the ethics of disseminating intelligence reports. Instead it becomes a story about whether Daniel’s busy schedule keeps him from spending time with his unfeasibly beautiful girlfriend (Alicia Vikander). This misses the point.

“The Social Network”, the film which has most in common with “The Fifth Estate”, opted for a similar angle, in that it observed the founder of Facebook, Mark Zuckerberg, from the perspective of his meeker friend Eduardo Saverin. But there was no question that Zuckerberg was the film’s protagonist, whereas “The Fifth Estate” reduces Assange to a shadowy supporting character. That he is sidelined is all the more frustrating for the fact that Benedict Cumberbatch delivers a mesmeric performance playing him. Mr Cumberbatch isn't especially like the real Mr Assange, apart from the white hair and the Australian drawl, but as he bobs around—never at rest, never comfortable in his own greasy skin—he’s so enthrallingly weird that this hardly matters.

Mr Bruhl fails to make the callow Daniel anywhere near as riveting. Mr Condon livens up proceedings with the techniques used in every film about people sitting in front of their laptops: he keeps the camera lurching, he cuts to a different shot every half-second, he flashes captions all over the screen, and he pumps up the techno soundtrack. He also tries to fill the Assange-shaped hole in the film with subsidiary characters, including Laura Linney and Stanley Tucci as American diplomats, and David Thewlis and Peter Capaldi as the Guardian staffers who negotiate to put WikiLeaks’s scoops on their newspaper’s front page.

But both the whizz-bang pacing and the sprawling cast serve only to over-complicate an already complicated narrative. Viewers who haven’t been following Mr Assange’s fortunes, or who haven’t seen Alex Gibney’s superior documentary, “We Steal Secrets: The Story Of WikiLeaks”, will be forced to head to Wikipedia after leaving the cinema. With its cough-and-you’ll-miss-it reference to Bradley Manning, and its fudging of WikiLeaks’ cessation in 2011, “The Fifth Estate” lacks the transparency that Mr Assange is always lecturing people about. But what it lacks most of all is a real portrait of Mr Assange himself, however elusive the man may be.

"The Fifth Estate" opens in British cinemas today