Here's a movie that deals with death and grief without hysterics, dramatic speeches or showy, Oscar-grubbing performances. Michael Winterbottom's Genova has a logline that sounds maudlin and turgid – after she inadvertently causes a car accident that kills her mother, a young girl starts seeing mom's ghost – but the movie turns out to be understated, down-to-earth, quietly sad. This is Winterbottom's most intimate film since 9 Songs, and one of the highlights of his career.

Genova has the wherewithal to show its characters dealing with loss in ways that aren't inherently cinematic. It would have been very striking, for example, to have the newly motherless children – the teenage Kelly (Willa Holland) and the preteen Mary (Perla Haney-Jardine) – scream, rage at the world, and slam doors in the face of their well-intentioned father Joe (Colin Firth) before concluding that Family Sticks Together. And in a film like this, I would have guessed that Joe would spiral into an alcoholic depression, or perhaps start a tumultuous, guilt-ridden affair with the old college friend (Catherine Keener) who comes back into his life.

Those are the arcs I would have expected to see. But though a couple doors do get slammed, Winterbottom's characters aren't here to amuse us or push our buttons. Their reactions to the tragedy and their ways of adjusting to a new life in the titular city all paint a much more nuanced picture – and the effect is more heartbreaking than any number of manipulative stunts could have achieved. Take Mary, played by a wonderful Perla Haney-Jardine as a girl who seems incredibly fragile but keeps blindsiding us with her resilience. She has nightmares, cries, and sometimes wets her bed, but it took me until an hour into the film to realize the depth of her guilt and pain. When it finally dawned on me how hyper-conscious of everything she had been all along, I nearly burst into tears myself. Hollywood loves little kids who are preternaturally plucky and courageous, but never portrays them with this much subtlety and sensitivity.

It similarly takes us a while to figure out the full extent of what's going on with Kelly. At first, she seems to display a typical movie reaction to her mother's death, withdrawing into herself and taking solace in cynicism and bottled-up anger. But we soon realize that it's not that simple. Her actual response is much darker and, chillingly, more familiar than mere withdrawal: it's self-absorption, the notion that this tragedy entitles her to do whatever she wants in the name of recuperation, or possibly karmic balance. Winterbottom observes this with sympathy and generosity rather than contempt; Kelly is sometimes cruel (sometimes remarkably so, as wounded teenagers can be), but she's not hateful.

Joe is loving and patient, but oblivious in barely discernible ways. Watch for the scene where Kelly says something spectacularly hurtful to her little sister, and Joe's only response is to chastise her for dropping the f-bomb. He means well, but he's grieving himself, and doesn't always understand. He tries to talk to Mary, but what he has to say seems feeble and clichéd. In a lesser film, he would have lost his temper; here, he never does, but in a couple of scenes you can see him straining to hold on to it.

Then there are Mary's visions of her mother, played by Hope Davis in a tender, brief performance. Ordinarily, I would object to the ghost's appearance as a cheap ploy, a way for the film to avoid dealing with the finality of death. That's the way it plays here too, at first. Then, when we begin to see the full extent of the pain wracking the little girl, we realize that the ghost isn't a ploy at all, but an absolute necessity. It's the only thing keeping Mary afloat.

The climax – probably the only Big Moment in the film – indulges in a contrivance that I readily forgave when it was followed by a moving, stubbornly low-key ending. It's a triumphant ending, actually, but you had to have watched the movie carefully to know it. "Life goes on" can be a powerful sentiment.

Genova gives us a warm, detailed glimpse of these people as they ebb and flow toward recovery. It loves them, and wishes them well, and wants to show them to us in their full and flawed humanity. It may end up going on the books as "minor Winterbottom," but "minor-key" would be more accurate. It's a terrific small film, a lovable TIFF underdog.