• TOP 10 FILM

After receiving an email from "Citizenfour", Poitras is alarmed by secret documents proving that America's telecommunications companies are betraying their customers by handing over private material. And it's even worse for non-Americans. So Poitras heads to Hong Kong to meet the whistleblower, Edward Snowden. She documents the process as journalists Greenwald (from Salon) and MacAskill (The Guardian) plan to break the story, including the revelation of Snowden's name. At which point he's aware that officials will divert the story: "This is not about me," he says. "These are public issues."

Snowden knows how this will end for him, but feels someone has to tell the truth. And where this goes is astounding. Greenwald's partner is threatened in a nine-hour interrogation at Heathrow, President Obama speaks about the case using slippery rhetoric, the European Court steps in. But through it all, there's no possibility for justice, no rule of law and no mention of ethics.

Poitras establishes an urgent tone, building suspense without hyperbole. She knows she's being watched (she has already fled America for Germany). And as she films Snowden's conversations with Greenwald and MacAskill there's a constant sense that anything might happen (a fire alarm causes everyone to freeze). Mixed with this is jaw-dropping news footage of officials everywhere lying through their teeth. And of course, the US government goes after the messenger rather than those who are illegally stealing people's private data or abusing their power.

The focus on Snowden adds details we could never imagine, including the chance to watch his reaction to his own breaking news. He comes across as knowing and articulate, reluctantly releasing these documents because he fears for his own nation's lawless behaviour. Meanwhile, his girlfriend Mills keeps in touch as mysterious construction sites pop up all around her home. Through it all, Snowden has no idea what will happen next, noting that "it's scary but kind of liberating".

Poitras also fills in staggering details of the data-gathering programme, which everyone in the government knew about. Using anti-terrorist laws, officials no longer need probable cause: they collect absolutely everything (email, computer use, phone calls, credit cards, passwords, photos). This "full take" is used globally without targeting, just collecting information in case it's needed later. But what are the consequences of eliminating privacy? There can be no free speech without the ability to speak privately, so this information can be used to stop competition, opposition and protests. In other words: it's totalitarian dictatorship. And liberty itself is the collateral damage.

These are Austria's national treasures, and these people work with priceless artefacts every day. The cameras merely observe everyone from cleaners mopping the floor and polishing the glass to executives discussing marketing strategies. Some are hanging or moving paintings, others are restoring them. Everyone approaches their job with genuine care, whether examining and repairing artwork or judging the merits of a typeface in an upcoming advert. Meanwhile, a family arrives to donate their patriarch's vintage military uniform, and museum staff visit an auction house in search of bargains.

Director Holzhausen shoots all of this in a fly-on-the-wall style, watching everything without any written or voiceover commentary. It's not difficult to work out who these people are by watching what they do. And there's a subplot drawing attention to a focussed goal: reopening the Kunstkammer, a museum within the museum that has been closed for some 10 years. The precious paintings and objects in this imperial collection are of primary focus as the staff gets ready for the grand opening, which will be attended by Austria's president.

Anyone who's visited an art gallery will love this glimpse of the workings behind the scenes, from ripping off old wallpaper to boardroom meetings about budgeting and ad campaigns. It may be somewhat straightforward in its approach, but the filmmakers continually catch moments of earthy humour and exhilarating discovery, mainly because this movie takes us places most people never go, whether prowling through the astoundingly vast basement archive or riding a scooter through a research library.

The film is packed with witty touches, such as when cleaners dust a naked statue or restoration workers "operate" on a polar bearskin rug. It's fascinating to overhear discussions about how a painting has been altered through the centuries, as well as arguments about where to place it in the new gallery. Not to mention following an exterminator in search of signs of moths. In other words, the film creates a terrific sense of the range of people who keep a national gallery running. So visiting one will never be quite the same again.

In 1975 Lanzmann filmed an interview in Rome with Rabbi Murmelstein, the last Elder from the Jewish ghetto in Terezin (aka Theresienstadt), Czech Republic, and the only Elder to survive the war. A controversial figure because of his position, he was reviled by the Jews so never travelled to Israel, remaining in exile in Italy. "I survived because I had a tale to tell about the Jewish 'paradise'," he says, referring to Eichmann's claim that Terezin was the "model ghetto". In reality it was a place of terror, with hangings for minor crimes and mass deportations to Auschwitz. Murmelstein says he was "between the hammer and the anvil" and only tried to deaden the blows.

Interspersed among Lanzmann's conversations with Murmelstein are scenes shot in the present day, as Lanzmann walks through the various settings reading from Murmelstein's 1961 memoir Terezin: Eichmann's Model Ghetto. This gives startling insight into now-benign locations that were once the site of hideous atrocities. It also vividly captures the sense that the Jews believed they were being sent to a paradise, even though everything about the Nazis' migration policy was dodgy (Hitler planned to send the Jews to Madagascar until Britain recaptured it).

More than 140,000 Jews traveled to Terezin between 1941 and 1945, as the Nazis' Final Solution shifted from persecution to emigration to extermination. The film brings unnerving insight to the situation, such as how annexing Poland, Austria and the Czech Republic brought even more Jews under German control, changing their plans. And yet Hitler kept telling them they were being sent to a wonderful new place. So Lanzmann's inclusion of paintings by Jewish detainees has a haunting power, as does footage from a 1944 German propaganda film about the joys of life in Terezin.

So even if the film's three-and-a-half-hour length feels excessive, the material carries a historical imperative. And it becomes strikingly personal when Lanzmann challenges Murmelstein for being so clinical as he describes the horrors he witnessed. "I didn't have the right to start crying," Murmelstein replies, noting that he had to think of practical ways to help people survive. And in the end, he refused to run, was tried and acquitted. And subtly showing how he really feels, the title of this film is how he refers to himself.

Without any context, a fixed camera merely shows people ascending and descending the mountain in single takes that last the length of the 10-minute journey, punctuated by the blacked-out stations at either end. Quite a few elderly passengers comment on how much more difficult life used to be, back when they had to hike up to the temple. While younger riders take selfies and snap photos of the views. One journey is taken by a group of nervous goats, and another by two musicians who tune their instruments and play them as they travel.

But we never see the beautiful scenery some of them talk about (or the temple for that matter). And several of the journeys are taken in inexpressive silence that says nothing at all; the first spoken word in the film is 25 minutes in. Thankfully, there are some entertaining moments, such as the three cheeky young guys with long hair, heavy-metal T-shirts and a mewling kitten. Or three chattering grannies telling stories. Or two women struggling to eat ice cream bars before they melt.

The only realinterest is who will be on the gondola when it re-enters the sunlight and whether we'll be looking up or down the hill, going forwards or backwards. There are no production values to speak of, the filmmaking essentially consists of a concept and editing decisions. Directors Spray and Velez have no interest giving us information about this place or culture beyond the faces, clothing, objects being carried and overheard conversations.

So while much of the film is bone-dry, the conversations feel utterly riveting by comparison. One older woman wryly philosophises that going uphill is hard, but coming down is easy. The married couple that reappears later in the film says that "it's fun going to the temple", even though it doesn't look like they're enjoying it very much. And the three rockers comment that they should make a music video on the cable car. If only.