You shouldn't box him in

You Are Making a film with a star who is not a strong swimmer, and you have to shoot a scene in a quarry that is 350 feet deep. For the director this is not a dilemma. You don't exactly lie to your star - in this case the noble and industrious John Turturro - just tell him that the water is "25 feet deep ... in places".

The day before shooting, a local newspaper headline reads "Expert Swimmer Dies In Quarry", and the story beneath reveals that the drowned man had been bitten by a poisonous snake. Again, no problem: just make sure all copies of the paper are removed from the set. Finally, on the day of the scene, an understandably nervous Turturro stumbles and breaks two toes after you tell him to run faster across some rocks. That's OK, though: keep on shooting. This is no time to lose focus.

These are just a sample of the many directorial misdemeanours described in a revealing new film diary entitled Notes From Overboard. If Tom DiCillo, the writer-director of Johnny Suede, Living In Oblivion and the forthcoming Box Of Moonlight, hadn't penned it himself he might have been thinking about suing for libel. As it is, his account of the filming of Box Of Moonlight, which is being published with the screenplay, paints as commendably clear a picture as one could wish for of the monomania, deceitfulness, paranoia, and vicious moodswings that are the essential building blocks of the film director's trade.

DiCillo's is a business currently subject to an absurd degree of mystification. With just about every new film release now coming complete with its own fawning three-part TV documentary, and bookshops awash with film screenplays cunningly targeted at people who think they are too cool to read proper books, Notes From Overboard is a welcome antidote to the prevailing mood of cinematic self-congratulation. Better still, Box Of Moonlight is a film of sufficient deftness and intelligence to deserve to have its screenplay and director's diary published.

One of the most entertaining things about DiCillo's reminiscences is the candour with which they detail the thousands of cruel ego pinpricks that seem to make up a film director's day-to-day existence. Encountering this intimidatingly suave New Yorker on the London leg of his publicity round, further evidence soon presents itself. Far from the dishevelled walking shadow of independent film-making archetype - like the broken, shambling figure played so affectingly by Steve Buscemi in Living In Oblivion - he is expensively dressed and has frighteningly well-organised hair. But that still doesn't mean things always go his way.

On arrival at his small but select Piccadilly hotel, each journalist is handed a freshly printed sheet by a slightly apprehensive publicity woman. Outlining DiCillo's career to date, it emphasises the fact that he did not start out as a cinematographer, though he worked as one on Jim Jarmusch's first two films. The buzz of conversation in the lounge dies down for a second, and it is possible to overhear DiCillo being interviewed across the room. "So, Tom, you started out as a cinematographer?"

As Box Of Moonlight's central character - Al Fountain, an awesomely anal electrical engineer - Turturro undergoes a myriad of such tiny slights. Having watched him shine just to one side of so many films, you're pleased to see Turturro at the middle of things for a change. Especially in a role that stretches him to such effect: forcing him to imbue the apparently straightforward figure of the buttoned-up man who unbuttons one Fourth of July with all sorts of unexpected resonance.

On the face of it, Box Of Moonlight is a simple story in the mould of John Hughes's great Planes, Trains and Automobiles - uptight family man loosens up with the help of borderline psychotic (the loveably unhinged Sam Rockwell taking the John Candy role). But the film is a good deal deeper than it initially appears: beneath the lustrous, quicksilver surface, there are some intriguing political undercurrents. "I think the conclusion it comes to," DiCillo maintains stirringly, "is that every single institutional idea that we are confronted with needs to be personally investigated."

Could he explain how he thinks the film does that? "The Fourth of July is supposed to be a celebration of freedom [It's nice of him not to add "from British imperialism" at this point]. I value the kinds of freedom America lets us have, but the whole holiday has basically become a three- day weekend for Americans to get drunk and shoot off fireworks, which makes you think about the idea of the freedom it's supposed to be celebrating. The question Box Of Moonlight asks is, where has that appreciation of personal freedom gone to?"

You don't need to have seen Independence Day to appreciate that this is a question which can be as fruitfully asked of the film-making community as of any other in America. In his diary, DiCillo likens the experience of watching modern movie trailers to "driving behind a garbage truck with drunken garbage men hurling the refuse at your windscreen". While this might seem extreme, it's true that there is an almost forbidden pleasure on offer in Box Of Moonlight - the joy of subtlety. The gradations of Fountain's character - and indeed that of his nemesis/helpmeet "The Kid" - are finely measured.

Too finely for some. "It would be better if you could see he really changes," was one unsympathetic response quoted by DiCillo. "He should grab his wife's ass at the end, then we'd know." The director rolls his eyes. "I actually had a woman say that to me. The idiotic thinking that's around just blows my mind!" This is not the first interpretation of one of his films to meet with DiCillo's disapproval. Someone has actually had the temerity to suggest that Living In Oblivion - one of the most illuminating and least self-indulgent movies ever made about the men and women behind the camera - was actually a satire on Hollywood.

"Would you show me where Hollywood is in that film?" DiCillo demands, his improbably tanned features creasing in anguish. "The whole story is very specifically about the idea of independent film-making, which has its own cloak of superficiality around it that I wanted to poke a hole in." At least Hollywood people know they're evil ... "And they admit it! At least if someone pats you on the back in Hollywood, you know when you get home you've got to pull the knife out. For all the independent sector's pretensions to being different, everyone's basically still clawing at each other trying to get to the golden apple."

It sounds like a nightmare. "I've never really done this before," DiCillo says conspiratorially, "but I'm going to give you a personal illustration. When I grew up my father was in the military, so we were always moving from town to town. At every new school I went to, there would be two troops - the nerds, with glasses and pens in their pockets, reading Popular Science; and the hoodlums, who'd all be into punching girls really hard on the arm."

Is this a direct analogy with the US film-making community? "Put it this way," DiCillo replies, smiling. "I remember getting off the bus and thinking, 'Well, which side am I on?' And I like to think my films might have that same sort of complication about them."

'Box Of Moonlight' opens on 18 April. Tom DiCillo's screenplay and diary, 'Box Of Moonlight and Notes From Overboard' is out tomorrow from Faber (pounds 8.99).