Blue Valentine (15)

There are scenes of such exquisite sadness and performances of such raw pain in Blue Valentine that you may wonder by the end why it isn't quite the satisfying movie it ought to be. Writer-director Derek Cianfrance brings great delicacy to this portrait of a marriage, preferring to nudge the audience along rather than semaphore every last message, and at times you could almost swear you're watching two people fall out of love, instead of just a brilliant impersonation of it. Yet still, there's something undernourished in it.

It begins with the disappearance of the family dog: a bad omen. Dean (Ryan Gosling) asks his six-year-old daughter Frankie (Faith Wladyka) to check the kennel, to no avail; it's only later in the day that his wife Cindy (Michelle Williams) tearfully whispers to him that the dog's dead, and it's her fault. She forgot to lock the gate, not for the first time. Slowly, in sequences of quotidian domesticity, we realise that all is not well in this marriage, and Dean's plea for a child-free night out to restore some romance looks like a last desperate roll of the dice. That the room he chooses in a tacky themed hotel is called "The Future" seems a particularly crushing irony.

The narrative trick of the film is simple but effective. Cianfrance gives us scenes of the couple's breakdown intercut with scenes of their courtship, six years earlier. The extra twist is a complete absence of title cards or dates to indicate which timeframe we're watching. The Dean of the present-day is a house painter, balding, and drinking, though we sense still a boyish playfulness when he's around their daughter (he spins her a sweet yarn that their lost canine has gone off to Hollywood to become "a movie dog"). Cindy, a hospital nurse, is more brusque and impatient, a little martyrish, though it's a subtlety of the film that our sympathies keep shifting between husband and wife as the fissures in their relationship broaden.

The jolt comes when the story takes its first unannounced step back in time. This Dean is a happy-go-lucky removals man in Brooklyn, the sort who puts himself out by decorating the room of an old man, a complete stranger, just to make him feel welcome in his new care home. Across the corridor he happens to catch sight of a young woman visiting her grandmother. This would be Cindy, who's had it up to here with difficult men – her dad (John Doman) a dinner-table shouter, her boyfriend (Mike Vogel) a jerk – and responds to the quirky, attentive Dean, improvising a little tap dance while he serenades her on ukulele with "You Always Hurt the One You Love" (those ironies keep coming). He's more romantic than she is, and makes her the centre of his life, so that when she tells him she's pregnant – and that it might not be his – he comes to her aid in a way that perhaps not many men would.

Of course to witness love in its first bloom of hopefulness, and simultaneously to know what sorrow lies ahead, could not be anything other than poignant. Back and forth the film shuttles, watching, listening, trying to work out what went wrong between these two. It doesn't supply a definitive answer, because the key middle years of their relationship are left unexplored. But it does give us clues, notably in Cindy's ambition to be a doctor, which falters once she decides to have a child. And at the first meet-the-parents dinner we discover that the amiable Dean rather lacks drive (no high-school diploma) and is slightly compulsive in his joking – if indeed the name "Dr Comstock" really qualifies as a joke. Their attitude to marriage reveals itself as fundamentally at odds – he sees it as something static, she as something dynamic. When she gently complains that he could be so much more if he used his "potential", he doesn't understand her: he's got exactly what he wants, which is her, them, together.

The bleakness of this is partly offset by the committed performances of the leads. Michelle Williams, who delayed taking the role in the wake of Heath Ledger's tragic death, projects a mater dolorosa whose passive-aggressive victimhood isn't always attractive but never feels inauthentic (she has done variations on it before in Wendy and Lucy and Brokeback Mountain). Ryan Gosling is a livewire as the blue-collar working guy, not dim but not quite smart either, too ready to put his feelings on show. In one of their final flailing arguments he quotes their wedding vows, and begs her, "Please, tell me what I should do." ("Get yourself a shave," muttered my wife – be careful about choosing who watches this with you). But however admirable the acting and Cianfrance's willingness to leave things unspoken, it remains a draggy experience, with too little for the eye and the mind to feed on. Reticence is both its strength and its weakness. The couple's expectations are different, but not so different as to make them irreconcilable. Many marriages (one suspects) have survived on much less. The film does not yield enough dramatic incident to back up its emotional meaning, namely: this marriage cannot go on.

It may turn out to be one of those films men and women have terrible rows about afterwards; or it could be so dispiriting that they'll come out of the cinema and not want to say anything at all. The image I'll take away is one towards the end, when, following a furious bust-up, he yanks the wedding ring off his finger and throws it away. Cut to the next scene, and he's scouring the bushes in search of it. Rancour and remorse are wrapped that close in Blue Valentine.