‘I thought it was supposed to go on for another half hour!’ said a man in the foyer on the way out. ‘When the alien got burnt to death I thought thank fuck for that.’

Before you get annoyed with me for giving away the ending, let me explain that this is one of those films where plot takes a back seat. More than that, it’s been tied up, gagged and locked in the boot. I can’t stand it when people give away the ends of films, which is why I never read reviews before going to the cinema. Too many reviewers have no respect for plot.

So I didn’t know that much about Under the Skin, only that it was based on a book by Michel Faber, which I hadn’t read, and that it starred Scarlett Johansson as a sexy alien who lures Scottish hitchhikers to their untimely fates. And that lots of people – and not just Total Film – were calling it a masterpiece.

Having watched Under the Skin, I still don’t know that much about it, although I do now know what Scarlett Johansson looks like naked. This is the film’s biggest draw along with some alien video art and some pretty stills of the Highlands that could have been produced by the Scottish tourist board. (Quick, this could be your last chance to see it without a visa!)

We see rather too much of the Scottish countryside, its scary forests and desolate moorland and fierce seas. Clearly the director, Jonathan Glazer, was worried that too much Scarlett and not enough scenery might jeopardise the film’s artistic integrity. He seems to have been working to a ratio of one second of tits to three minutes of glen.

Glazer is careful to show another side to Scotland too. So we also see plenty of fat, poor people in depressing Glasgow streetscenes, screeching girls in scuzzy nightclubs, and motorways.

And anyway, the nudity’s fine because Scarlett is in an ugly brown wig although not – as Faber’s novel has her – in thick spectacles. I downloaded the book on my way home from the cinema because I was hoping it would answer the big question the film leaves hanging: just why has an alien been sent to earth to capture Glaswegian men?

In the book the doomed hitchhikers are stabbed in the bottom with a tranquiliser-filled syringe that shoots up from beneath the passenger seat as soon as Isserley, the alien, has established they don’t have any family to worry about their whereabouts. The specimens are then sent back to her planet, where they end up as tasty fillets on the dinner plates of her fellow aliens.

In the film, Scarlett tricks the men back to her house on the promise of sex, and does a striptease while her victim unknowingly wades into a dark pool. It is very stylised and lovely to watch, but you have no idea what the point of it all is, apart from an excuse to see Scarlett’s bum. There is a fine line between ambiguity and laziness.

I wouldn’t say the film was terrible. It’s beautifully shot, has a sense of humour in places (the moment when the scrawny Celtic fan peels off his shirt got a laugh from the audience), the score, with its deliberately Psycho-esque violins, is fantastic. It also contains one of the most horrific scenes I’ve ever watched, where the (literally) heartless Isserley leaves a baby to be washed away on a beach.

But if you’re someone who cares about such shamefully middlebrow things as storyline, character development and dialogue, then I would say you’re better off buying the book and looking on Google Images for scenery+scottish+highlands and scarlett+johansson+naked. With the safe search off.

Anna Baddeley is a freelance journalist and editor of The Omnivore

Tags: Film, Glasgow, Highlands, Jonathan Glazer, Scarlett Johansson, Scotland, Under the Skin