A Teheran apartment block is seemingly on the point of collapse as the occupants are roused by furious banging on doors and voices urging them to get out and save their lives if not their possessions. The cast of a theatre group sit in barbers' chairs backstage before the evening performance, having their make-up painstakingly applied. These are the bookends to the latest film from director Asghar Farhadi, one of the second wave of Iranian film makers following the inspiration of Abbas Kiarostami and Majid Majidi. I've now seen five of his films; they've all been interesting, sharing a dense structure of incident and theme; they also inhabit a place where metaphor and naturalism meet, if not collide.

A middle-class couple in their thirties are amateur actors on the verge of the dress rehearsal of Death of a Salesman, when they are forced to evacuate their home. A cast member finds them a temporary flat. They find their lives turned upside down as, in consequence of the former tenant having been a sex worker who has left her possessions behind her, their personal security and their relationship are all but wrecked following an assault.

This is a multi-faceted drama spreading itself across the genres of social comment, quasi-thriller and most especially psycho-drama. Criticism of jerry-building property builders and the perils for a woman of reporting an assault with a sexual element to it are instances of the director's concerns reaching beyond his two main characters. The thriller aspect is developed in the second half of the film as the husband decides to seek his own retribution on the intruder, and an element of melodrama and slightly blatant coincidence creep into the events of the final scenes.

But this is primarily a complex psycho-drama. The fact that Farhadi chooses to cut away from the crucial assault so its precise nature is never evident makes its impact all the more unsettling for the viewer. Yet his hand-held camera snakes in and out of cramped bedrooms, corridors and staircases, inexorably pursuing the bewildered couple as they grapple with issues of authority and decision-making between them. This contrast of camera fluidity and constraint vis a vis the geometry of the settings and the characters' increasing emotional disconnection yields a tonal and emotional friction that I found very stimulating. The wife's predicament of loss of confidence and outright fear following her assault slowly becomes less important than the husband's assertion of his own honour and face-saving, both at home and at the theatre, and also in his capacity as a teacher whose relationship with his students undergoes unpleasant modification. Here the script is examining issues of masculinity that parallel neatly the effect in Death of a Salesman on Willie Loman, who finds himself surplus to requirements as times change and he cannot change with them, and whose psyche and domestic life are shattered.

The care with which the film has been made is evident everywhere. The opening sequence where the peril to the apartment block is shown in telling detail as much by means of cunning sound effects as by the progressive cracking of the window panes and the glimpsed presence of a reptilian bulldozer burrowing away below the block, resembling one of the infernal machines from Mars in Spielberg's War of the Worlds. The spaces of the theatre are bathed in a warm, womb-like light in painful contrast to the couple's shadowy, possessions-strewn flat and its stark basement car park.

This is a minor masterpiece from a film maker at the top of his game.