When an American tourist is accidentally shot in the Moroccan desert, the events have repercussions around the world. The holidaying couple struggle to survive in a country where few speak their language. A Mexican nanny is forced to take two American children over the border illegally. Two young boys get involved in a crime they didn’t intend to commit and a deaf teenage Japanese rebel discovers her father is being sought by the Tokyo police. Circumstance connects them, but they are all united in their sense of loss and isolation. Separated by culture, language and a lack of understanding of their surroundings and themselves, they all struggle to connect with the world.

It’s a film that feels like hard work because it is so unremittingly bleak throughout. There are moments of tenderness and even the odd laugh, but there aren’t enough of them to counter the suggestion that we’re all the same because we constantly misunderstand each other either accidentally or on purpose. But while González Iñárritu is very good at showing the existential ties that bind everyone together, he is also adept at showing what separates us from one another. The clearest example of this is where he juxtaposes Susan’s screams of pain with the silent world in which Japanese schoolgirl Chieko lives. The director’s palette bears the bleakness out, focussing on bleached-out greys, gritty browns and sterile whites. It means there isn’t a great deal of warmth (visual or emotional) in the film, so it’s hard to become engrossed and care about the characters. The film only really springs into life in the section set in Mexico at a wedding where the director’s love for his native country shines through in a blaze of colour. It is a thorough piece of filmmaking that follows the emotional journeys of its protagonists very closely but doesn’t allow the viewer a wider overall perspective. The lives of its players aren’t interwoven strongly enough.

You can see Brad Pitt acting his socks off as American tourist Richard. But that’s the problem; it’s a role that doesn’t come easy to him and you can see where he ends as an actor and the part begins. There’s too much technique and not enough real emotion and he has neither the experience nor the presence to convince as a man in his fifties. Cate Blanchett gives a consistent but wholly unlikeable turn as Pitt’s on-screen wife Susan. She’s brittle and needy, sharp and fragile and a bit of a bitch, to be honest. But it at least feels like she’s living the character’s trauma.

The original music by Gustavo Santaolalla is as eclectic as the characters and scenarios it accompanies. He creates a strong sense of place with Arabic strings for Morocco and traditional-sounding mariachi style music for Mexico. It blends neatly with the use of local pop music on the soundtrack, from techno-influenced J-pop for Japan and loud Mexican pop for south of the border. But there is no unifying theme for the majority of the musical choices. Every time the composer wants the audience to feel something, he goes for mournful solo instruments such as acoustic guitar, piano or muted keyboard. It’s only once we get to the end that Santaolalla builds more complex arrangements that feature plucked strings. But it never really holds together as a body of work.