The first third of this movie is nothing short of brilliant. The rest of it's so nonsensical you could turn the movie off and feel like you've watched a very prescient short film.

Robin Wright plays herself, an actress of grace and poise in a Hollywood that only cares about youth. For some reason she lives next to an airport in a miniature hangar with a smarmy daughter (Sami Gayle) and a son who seems to be autistic (Kodi Smit-McPhee) and roles are drying up.

But when a unique new offer comes from a slimy Miramount studio executive (Huston), even her long-suffering and supportive agent (Keitel) thinks she should do it.

They want to give her a handsome one-time payment for the right to use her CGI likeness in any project they want, the conditions being that she'll never act again and she gets no say in the roles her likeness will act in.

Despite her misgivings, Robin finally agrees – she has a family to take care of, after all – and the film's most arresting visual comes when she enters the room where they scan her.

It's a huge chamber with a spherical frame covered in lights that fire in a sequence as she laughs, cries, smiles, movies and emotes in every possible way her future CGI self could possibly need. It's a haunting and beautiful scene with Wright in the foreground, Keitel speaking a sombre monologue over the loudspeaker to bring the sadness or happiness out in her and a lightning storm of lights flashing around her.

The film up until that point says a lot about the durability and disposability of the modern movie business, how Hollywood is increasingly technologised, obsessed with cutting costs and trying to control the last independent asset it has – professional artists with minds of their own.

Then we lurch 20 years into the future with the much older Wright arriving at a desert checkpoint on her way to a swanky hotel where she'll take part in the conference of the title.

As soon as she drives through the gate it becomes an animated film. It's an interesting choice, but from then on you'll have so little idea what's going on you won't know if it's just an aesthetic choice like the one writer/director Ari Folman used in his breakout hit Waltz With Bashir, or whether it was supposed to somehow be a representation of reality.

She talks to her kids and agent on the phone, goes to see a doctor (Paul Giamatti) who likewise exists in both places and gives a speech to the crowd, but a group of underground rebels uses the moment to hijack the hotel. Robin also falls in with a scruffy animator (Jon Hamm), but you'll have no idea what he has to do with anything either.

Folman uses the medium to wrangle some impressive visuals, but the plot turns so nonsensical it's a huge letdown after the opening act says something so special.