Lea (Elsa Zylberstein, left), a university academic, becomes reacquainted with Juliette (Kristin Scott Thomas), who has just been released from prison in I've Loved You So Long. (Thierry Valletoux/Sony Pictures Classics)

I’ve Loved You So Long opens with a close-up of Kristin Scott Thomas seated in an airport lounge, her face the same sooty grey as the smoke swirling from her cigarette. She looks like an Edward Gorey character — scooped-out cheeks and hollowed eyes atop a wispy body, barely there, staring through a window at nothing.

That face — blank and impassive, more handsome than beautiful — is the matter that holds together this achingly sad film, one that could only be French. If the language didn’t clue you in, the wine, candles, smoking and cafés might. This is French pain, people — the most painful, most poetic kind of all.

Scott Thomas plays Juliette, just released from prison — no spoiler here — to stay with the sister she hasn’t seen for 15 years. Léa (Elsa Zylberstein), an academic at the university in the eastern city of Nancy, flutters nervously but sincerely, inviting her sister into her scholarly life. She is as open as Juliette is closed, bursting with expressions of love. But Lea’s hugs are lost on Juliette’s bony shoulders, her shopping trips blandly endured. Juliette sparks to life just a little in the presence of Léa’s two adopted Vietnamese nieces. (Their adoption is significant, an oblique link to Juliette’s crime.) All of Léa’s heartfelt gestures are aimed at a woman who is, for all intents and purposes, a stranger, as Lea’s grumbling husband (Serge Hazanavicius) points out repeatedly.

The film derives an astounding amount of dramatic tension simply by withholding information; it moves like a mystery. In fits and starts, the reason for Juliette’s incarceration is revealed, and each revelation is like a splatter of paint on a canvas that becomes entirely filled only in the (not entirely successful) final scenes.

If the trick ending feels a little false, what comes first brims with genuine emotion. Welcomed by this new community in spite of her reticence and standoffishness, Juliette is forced back into the land of the living; she slowly begins to make an impression on life again. She develops relationships with two men: the police officer in charge of her parole (Frederic Pierrot), and one of Léa’s colleagues, a professor (Laurent Grevill) infatuated with this secretive addition to the party table.

Juliette’s guilt and self-loathing seem to point toward a natural, existentialist conclusion, but for all its sadness, the film turns out to be quite optimistic. This traumatized woman has to choose what kind of life to have: one of a living suicide, or one with some sort of pleasure, with love and human connection. Léa has her own brittleness — she terrorizes her maid — but she softens around her sister. As the two get to know one another, revisiting their shared past, they begin, in essence, to fall in love.

Juliette (Kristin Scott Thomas, left) develops a relationship with one of her sister's colleagues, a professor named Michel (Laurent Grevill). (Thierry Valletoux/Sony Pictures Classics)

If this were an American film — or Oprah — there would be talk of “forgiveness” and “healing.” Thankfully, until that final, messy ending, the sentimentality is well controlled, even allowing for some moments of dark comedy in the tsunami of sniffles. Ever self-brutalizing, Juliette picks up a man in a café and takes him to a hotel. Afterward, as he does up his pants, he asks, “Did you enjoy that?”

“No, not at all,” she says in her blunt-object way.

There may be one too many moments of soap opera melodrama, but mostly, writer and director Philippe Claudel, a novelist, shows great dramatic patience with his debut film; it never goes slack. Scott Thomas, such a resilient actor, is fabulous — she’d probably get an Oscar if that other French actress hadn’t used up the foreigner quota last year. In any case, Scott Thomas is bound to be nominated, and deservedly so: it is her reborn face that renders this portrait of grief unshakeable.

I’ve Loved You So Long opens in Toronto and Vancouver on Nov. 7, with other Canadian cities to follow.

Katrina Onstad is the film columnist for CBCNews.ca.