Tom Sutcliffe: Take a shot at what it all means

"Any reaction to the material is the right reaction." As diktats go you can hardly complain that this is over-controlling. Sean Durkin said it in an interview recently about his debut film Martha Marcy May Marlene. He'd been asked about the film's ambiguities, and – entirely sensibly, in my view – had declined to take the opportunity to diminish them in any way. If you're one kind of film-goer I can see that this answer might strike you as irritating. You assume that a film means one thing, that the director knows what that is and that, even if they choose to keep such information to themselves, it is available somewhere to make final sense of everything. You might be groping in the mist but you like to feel that you might actually hit something solid if you hit the right conclusion. Durkin's might just have been a simple way of saying "Aha... I know, but I'm not going to tell you". But it seems to hint at something grander than that, which is that uncertainty is at the heart of his film. Mischievously, I did briefly wonder how he'd react if his generosity about interpretation was really tested – if some earnest loon insisted that the whole thing was in fact a coded allegory on the folly of leaving the gold standard and adopting Obamacare, for instance. But then I remembered that I was on his side anyway, in the long, drawn-out combat between the dirigistes and the open-enders. Better Durkin's emancipation of the imagination than most directors' dictatorial control of it.

Martha Marcy May Marlene is about authority, in a way. It tells the story of a young woman escaping from an abusive cult and, in doing so, it shows her interactions with the cult leader – who employs a textbook combination of psychological grooming, charisma and straightforward threat to draw her in. Martha is vulnerable because nobody has told her before how wonderful she is, so when he praises her talents and her importance to his mission she is eager to please even more. And though she starts to have some misgivings about the kind of things that are demanded of her, it's still hard to break the submission to someone else's encompassing world-view. Like everyone else on the farm, Martha has willingly surrendered her vision of the world and replaced it with his. Which is, in one sense, what all of us do whenever we go to the cinema.

"This is how it is", says the director (implicitly) and we have very little choice but to accept it. Sometimes the attempt at mind-control won't take. I find it hard to believe that anyone could watch War Horse, for example, without becoming a stalls subversive, actively undermining Spielberg's account of reality. But with any half-way competent director we accept most things unquestioningly. Which got me to wondering a little about Durkin's almost anarchic disavowal of authority – at least as far as it affected this particular film and this particular subject. Durkin's Manson figure is played – very creepily – by John Hawkes, who looks questionable from the very moment you see him. There's never really a moment at which you believe he's without dangerous undercurrents. And though that pays dividends as regards the tension in the film – an uneasy sense that things are creeping steadily in the wrong direction – it also means that Martha's experience of the cult is viewed from the outside. We're scared for her when she isn't scared, because we can see what she can't.

And I found myself wondering what the film might have been if Durkin had behaved a little more like a cult leader and less like a democrat. From the opening frame he lets his images teeter between threat and benevolence. A child plays alone in the yard of a slightly run-down New England farm; neglect or an idyll? Any reaction is the right reaction, Durkin might say. But wouldn't the very creepiest account of cult submission be one that successfully enlisted us too, enlisted our sympathies on behalf of a misunderstood idealist? It would have to lie to viewers shamelessly, exploit their weaknesses, co-opt them into something awful. And then, when it was too late, they would discover how terribly they'd been manipulated. As a citizen I prefer Durkin as he is. He, as a director, perhaps could have been a bit more wicked.

Brush up in advance for HBO's latest gamble

Note to editors: It might be time to start preparing the journalistic casualty stations for viewers of Luck, a new HBO series about American horse-racing, starring Dustin Hoffman and directed by Michael Mann. The first episode goes out on 18 February and, if my experience was in any way typical, will be followed by a raging appetite for clarification. Even HBO appears to acknowledge that its new property might be baffling for newcomers, with a feature on its website for the programme called "The Luck Explainer", a comment forum where people can help each other through the tangle of arcane detail you encounter. This level of mystification has several sources. Firstly David Milch, Luck's creator and writer, loves gambling and owns his own racehorses, so he really knows his subject inside out. Secondly, Michael Mann is a director who has always responded to the idea of a sodality – a confraternity of men who share special knowledge and special experience. And thirdly, explanations within the drama are almost invariably clunky and break the spell. The audience has to feel a little out of its depth to feel there's any kind of real depth at all, though you have to be careful that they don't actually drown before they've learnt to swim. I confess that I swallowed a lot more water than I'd usually want to in Luck, and wished I'd consulted the Luck Explainer before watching for added buoyancy. But for anyone confident in the water already, I imagine it will be bliss.

Seen a 40-minute film recently?

Television is such a rapidly changing ecosystem that it hardly makes sense to talk of endangered species. The death of one programming type and the birth of another is the motor of the whole thing, after all. At one period a certain kind of studio-based sitcom is the dominant species and then some climactic change makes it fade away, to be replaced by constructed reality shows, or makeovers, or an old costume drama dressed up to pass as a new one. Even so, I increasingly find myself regretting the disappearance of the 40-minute television film – a format which used to be ubiquitous and is now vanishingly rare. This is partly the result of a tidying up of the schedules into neat interchangeable blocks that end on the half-hour or the hour. You still get the odd 30-minute programme to make that work but, overwhelmingly now, most films are an hour long (or an hour minus the ad breaks). And only a very small percentage of them can justify it. It's not that they aren't good films at heart, just that their broadcast versions are often flabby with redundancy and padding. They'd be too tight at 30 minutes, but at an hour they're having to look for ways to spin things out. I'm sure it's more convenient, but I'd love it if some commissioner would open a sanctuary for programmes that are just as long as they need to be.

t.sutcliffe@independent.co.uk