If one individual can be singled out as responsible for propagating the by-now cliché that Britain, or more precisely England, is a nation that has suffered an irredeemable decline since the Second World War it is John Le Carré. His hugely successful novels, starting with The Spy Who Came in from the Cold in 1963, may ostensibly belong to the genre of cold war spy thriller but they are also more conflicted, complex books: at heart, they are elegies for a once-powerful nation forced into embarrassing compromises and routine betrayals by the dictates of Americans, the despised 'cousins’ at the CIA. Thanks to deft repositioning, courtesy of his considerable talent, Le Carré the novelist successfully survived the fall of the Soviet Union. However, his central theme, already established back in 1960s, remains unmodified: how England, desperate to placate powerful and unreliable suitors, is willing to sacrifice the very people who still incarnate the country’s truest values.

In Fernando Meirelles’s vivid adaptation of Le Carré’s 2001 novel The Constant Gardener, latent English decency is epitomized by Justin Qualye (Ralph Fiennes), a junior diplomat posted to the British High Commission in Nairobi. And it is the murder of Qualye’s wife Tessa (Rachel Weisz) that both opens the film and begins the chain of events that will reveal the true nature of both Justin’s character and the establishment of which he was previously a complacent member.

By starting with a protagonist’s end, the film has to resort to flashbacks to persuade the viewer of the magnitude of Justin’s loss. Ominous hints as to why Tessa was murdered also need to be strategically placed. Director Meirelles elevates the labour of exposition with kinetic cinematography and judicious editing, as the film snaps back from the idyll of the past to the horror of the present. The camera in the scenes between Justin and Tessa mimics the viewpoints of the characters as they discover each other, so eyes take up the entire screen and intimate body parts are revealed abruptly, leaving the viewer momentarily searching for a focus. These scenes of emotional and physical vulnerability are brutally ruptured by showing Qualye’s visit to the African morgue to identify Tessa’s disfigured body—although we do not see her face, the fact that Qualye’s superior, Sandy Woodrow (Danny Huston), is reduced to vomiting when the sheet is lifted communicates the grisly sight more than effectively.

Aside from using different lighting to differentiate the past from the present (with the former presented in bleached tones), Meirelles, a Brazilian whose previous film was City of God, brings a fresh sensibility to depicting the locations Qualye’s journey encompasses, both in Africa and Europe. The Kenyan scenes feature the obligatory urban shanties, which the pregnant Tessa righteously insists on visiting, but along with the squalor, the vivacity of the place and its inhabitants is also conveyed. Such depictions of 'colourful’ Africa might be accused of indulging in mere exoticism, but it is the quasi-anthropological take on Europe that underscores the director’s attempts to sidestep a 'them-and-us’ portrayal. As Qualye searches for leads, he leaves Kenya and visits London and Berlin. The British capital is depicted in murky hues, whether through the battleship-grey of closed-circuit images or the beige decor of London clubland. Things might be better ordered here, seems to be the message, but where’s the humanity in this chilly world? Moreover, such a disorienting view of 'civilization’ might lead to other, more radical insights: for example, that the porter at Sir Bernard Pellegrin’s club, in his livery and his insistence on club rules being observed, is as bizarre as a village witchdoctor.

(In passing, there is one bravura pan with a didactic punch Eisenstein would be proud of—a dizzying 180-degree swoop taking the viewer from Qualye confronting a belligerent pharmaceutical executive on a lush putting green to a vantage point with a view of a vast teeming slum, over which a jet is hauling itself into the sky.)

Meirelles may treat his material in way that brings some equality between the Western and African perspectives, but the actual plot breaks little new ground. It is not giving too much away to reveal its fundamentals: Tessa—a trust-fund radical—spends her time in Kenya with a Belgian doctor of African extraction, Arnold Bluhm (Hubert Koundé), investigating why a pair of Western pharmaceutical companies seem to be so apparently generous by providing slum dwellers with medical treatment. It will not surprise anyone who has ever watched a conspiracy thriller with liberal sympathies (i.e. any conspiracy thriller) that the drug companies’ apparent generosity has a very dark side. But it’s not the predicable trajectory of Qualye’s subsequent journey to the heart of darkness that’s especially problematic—an audience familiar with the conventions can enjoy the ride for what it is. A far more troubling aspect stems from the impression that the deaths of scores of Africans merely serve as a correlative to Tessa’s unplanned sacrifice. Despite the director’s empathic treatment of the African landscape and people, the film cannot escape the fact that—true to the source material—the film is more interested in the fate of two attractive English people than the demise of hundreds of Kenyans.

That the film suffers from the kind of liberal hypocrisy it condemns doesn’t mean that it’s a failure. At worst it’s an interesting failure, with its intellectual blindspots covered, for the most part, by Le Carré’s astute plotting (in which the complexity eclipses the implausibility) and the more-than-professional performances. Both Fiennes and Weisz do their thinking-person’s film star stuff very well, but it’s in the supporting cast that the film really sparks. And, as per usual, it is the villains that get the juiciest roles. A trio deserves particular praise: Bill Nighy as Sir Bernard exudes languid menace; Gerard McSorley’s vulgarian drug executive is surprisingly sympathetic; and Danny Huston as the British High Commissioner is a scene-stealer playing a man whose morality has putrefied in the African sun.