Morvern Callar is based on a novel by Alan Warner -- which, I have been told, is taken up by the title character's internal monologue. None of that here. Samantha Morton, in the lead role, does not have a voice-over or a bunch of speeches, and heck, she hardly has any dialogue. What is the silence communicating? You tell me. But it's quite unreasonably fascinating, and that is the achievement of the movie.

It opens on Christmas Day. Morton awakes on the floor of her flat, lying next to her boyfriend, the darkness of the living room illuminated by rhythmic flickering from the lights on the tree. The boyfriend has killed himself. A note on the computer informs that he didn't mean to hurt anyone, and he loves his woman, but suicide just felt like the right thing to do. Morton seems stunned. Those babylike eyes are wide open, as they would be after physical shock. Her face is unmoving. There are louder, clearer forms of expressing oneself in situations like this, but they don't occur to her. She goes to work, attends a party, doesn't get rid of the body for several days, doesn't tell anyone what's happened. She simply does not decide how to react.

The boyfriend was a writer; Morton changes his name to hers on the front page of a manuscript and sends it off to a publisher. She goes to the bank, takes out some cash and arranges a holiday to Spain. In aid of what? Is ripping off the novel a subtle form of revenge, or is it a way to escape? Is the holiday for fun, or does it just feel like... something to do? We cannot say. But watching all this, my thoughts were racing. Morvern Callar is such an intimate examination of its protagonist's numbness that it could have been boring, but somehow it is not. We don't know what should happen, or what will, and the central dilemma is an unsolvable one, so we just accept whatever does happen. There are a few story turns, but the movie does not rest on them; it's about individual moments of mood, and an aimlessness that's actually sort of amazing.

The director is Lynne Ramsay, who did artistic and visual wonders with a miniscule budget on her debut feature Ratcatcher. That film is three years old, but the arthouse crowd continues to discuss it with breathlessness. Morvern Callar had a bigger budget, but it looks more raw; Ramsay must have used the money for the luxury of production time, so she could load her film with feeling and figure out ways to make the planning seem invisible.

Consider the sound design, which takes effects normally relegated to the background and plays with them, heightens them, until they're communicating things that the dialogue does not speak and the visuals can only go so far with. Think about the scene in which Morvern leaves a house party and ambles out onto the shore, walking along wet, sandy rocks and peering out into oblivion. It's subtle but effective, the way slight sounds of wind, water and sloshing footsteps build to evoke atmosphere, until I not only recognised the moment, but could swear I felt the cold.

Then there is Morton's performance, which, along with her work in Minority Report, makes her a strong candidate for Oscar nominations in two categories. The camera stares at her, but she is relentlessly unaware of it -- internalised, confounded, lost in feeling and unable to come to conclusions or even strong motions. What's going on in her head? It is hard to stop pondering the question.

I have read reviews of this movie that come to conclusions about what it all means and how Morvern Callar feels. Nothing in those articles seems wrong, and similar thoughts to those of other reviewers did occur to me while watching. But everything we think about comes from ourselves, not the movie, which simply looks and absorbs and sparks the imagination. There is little substance in Morvern Callar. It's done for pure effect. But what an effect.

(Released by Company Pictures; not rated by MPAA.)

Review also posted on www.ukcritic.com.