Happening

Among the films asking audiences to walk a mile in uncomfortable shoes at Sundance this year, along with Palm Trees And Power Lines and coming hot on the heels of Never Rarely Sometimes Always, was Audrey Diwan's adaptation of Annie Ernaux's autobiographical book, which drew on her own experience of abortion in early 1960s France. With the row over abortion rights still raging in the US, it was a timely moment for it to come to Sundance's Spotlight section after its Best Film Golden Lion win in Venice, as it is set against a time when terminating a pregnacy was illegal.

Taking us through the wringer of emotions - although never into melodrama - is Anamarie Vartolomei, who plays Anne, a 23-year-old bright college student with her life stretching ahead of her, until the fateful day her period fails to arrive. Diwan is unfussy in her style, adopting the claustrophobic's favourite Academy ratio and simply keeping us with Anne in the moment as she lives it, but making clear the broader backdrop, as her friend puts it when the world "pregnancy " is mentioned, "It'd be the end of the world".

Plucked strings in the score from Evgueni and Sacha Galperine mirror Anne's increasing anxiety as she finds herself in a lose/lose situation. If she goes ahead with the pregnancy, any hopes of finishing college and a career will be gone, but termination means risking her life both in terms of a potential prison term and physically if she is forced to go down the back-street route.

Diwan lets the cold hard facts trickle in as weeks are marked off at the bottom of the screen. What hits home is the sheer isolation of the situation for Anne who, with the father more or less in the wind, is left to decide what to do and becomes increasingly desperate as time wears on. There's the fear of someone in their shared dorm noticing her growing belly and the gradual awareness that even those who initially seem like allies may not be,like Jean (Kacey Mottet Klein), a classmate who she asks for help and who immediately tries to bed her because "there's no risk if you're pregnant".

Anne's quiet desperation is matched by a determination in scenes that don't need to be gory in order to be harrowing - although the sound design alone is enough to give you chills for a week. Vartolomei carries us into this space, a place where even crying out in pain must be avoided. As tense as a psychological thriller shot through with compassion, Diwan's film is may be a hard watch but it's also hard to forget.