TELEVISION / When the con-man met the gunman: Creativity at work in tall tales, corn-fields and a Parisian atelier. James Rampton on the weekend's viewing.

If the First Commandment for the BBC Drama Department seems to be 'thou shalt not produce a play unless Alfred Molina is in it,' then the First Commandment for the Viewer should be, 'thou shalt not object, because Molina is such a fine actor.'

In Screen One: Trust Me (Sunday BBC1), the latest vehicle driven by Molina, he played Harry, a compulsive liar (you knew this from the moment early on when he lay in a post-coital slump with his girlfriend and said 'I don't think it's important for men to have orgasms'). Avoiding histrionic con- man cliches, Molina delivered an ordinary-Joe barman in a sweatshirt and distinctly non-designer stubble, a man who only spins yarns to relieve the boredom. He looked and sounded so down- to-earth that his victims - journalists foremost among them - immediately swallow the tallest of his tales about sex'n'drug orgies on Everest or a pair of haunted trousers. Such a line as 'that's not a dodgy fan-belt, it's a black mamba' needs deadpan rather than melodramatic delivery.

Tony Sarchet's debut feature-length script was full of such neat one-liners. The crumbling state of a marriage was encapsulated in this exchange: Wife: 'I want a divorce.' Husband:'Did I leave the seat up again?' Director Tony Dow, an Only Fools and Horses veteran, gave the fantasist's life a suitably fantastical spin. As Harry's brother attempted to convince a colleague he was not gay, an elephant wandered across the back of the shot. Sarchet looks to be a writer of real originality; how many comic thrillers are resolved by the deadly combination of a self-heating can of soup and a sea-urchin?

An air of comedy also permeated the Sherlock Holmes-sounding 'Strange Case of Crop Circles' on Equinox (Sunday C4). Since the science programme first investigated the phenomenon last year, many cases have been exposed as hoaxes. Some people have been amused by the development. One Wiltshire local reckoned the circles were made by the Young Farmers, before adding 'I'd better not say anymore; my son-in-law's a Young Farmer.'

But the august Centre for Crop Circle Studies, which champions a para- scientific explanation, must have been more perturbed by the news - not least because it has emerged that some of the hoaxes were perpetrated by its own members. The Centre's arguments were further weakened when a competition intended to prove how difficult it was to fake complex patterns in the crops ended up suggesting exactly the opposite.

Jill Freeman's film, updated from last year's, concluded with an expert's view that 'the thing has gone rather sour now.' If the interest in crop circles continues to wane, many people stand to lose: the landlady of the pub that serves the Corn Circle Cocktail ('it makes you see corn circles after you've drunk it'); the tabloids, who will have to find another story to occupy acres of space during the Silly Season; and the broadcasters, who can't seem to get enough of the subject.

There was nothing so spicey in Music on 2 (Saturday BBC2), a slightly dowdy portrait of Katia and Marielle Labeque, the decidedly un-dowdy French piano- playing sisters. Perhaps they were run- down because of their schedule - a real 'If it's Thursday, it must be Barcelona' number. Or maybe it was the language barrier; Antoine de Caunes sprung to mind as Katia explained that 'It is good to be confrontated to music that you don't know about.' Or, possibly, producer Tamsin Day Lewis did not have quite enough material to fill an hour (we seemed to see an awful lot of shots of pianos being manouevred on to the stage and of bouquet-bestrewn ovations). But, the odd laugh apart, the documentary only really came to life when the sisters were at the keyboard. Their testing of a gaggle of grand pianos in a London shop may have been only for the benefit of a rather bored- looking assistant and a camera crew; but it was a performance worthy of the Royal Albert Hall.

So many documentaries these days claim to have enjoyed 'unprecedented access', you almost yearn for a film that boasts of being shut out. By contrast with many documentary-makers, however, Gina and Jeremy Newson made good use of their privileges in the final episode of their fascinating fashion series, The Look (Sunday BBC2), which profiled the designer Yves Saint Laurent. In one hilarious sequence, the feted designer sprayed so much hairspray on his barnet that the woman behind him started choking.

Throughout the series, the directors have shown a commendable sense of detachment from their subject. An early pronouncement by Saint Laurent that he detested the bourgoisie was repeated in between shots of Ladies Who Lunch splashing out thousands of pounds on his clothes. The whole tone of the programme did not encourage you to take too seriously the pundit who revealed that Saint Laurent 'is God', or the fashion historian who proclaimed that at one show the designer's 'workmanship was just unbelievable; I actually saw people crying.' Luvvies are obviously not confined to the theatre.