In 1970, Nicolas Roeg and Donald Cammell made an influential film about identity, Performance: A gangster on the lam hides out in the home of a faded, reclusive rock star, and the two individuals begin to merge. Writer-director Peter Howitt’s Sliding Doors is nothing like that.

Well, actually it is, but mostly by contrast. Both are set predominantly in trendy West London, and both trade on the city’s reputation for hipness. Whereas Roeg and Cammell’s London was decadent, ominous, and sexy, however, Howitt’s is cute, clean, and romantic. Surely it’s no accident that the movie’s pivotal scene takes place in one of the city’s newest and most brightly lit subway stations.

The complications begin when Helen (Gwyneth Paltrow) is brusquely discharged from her job at a PR agency in London’s financial district. She enters the nearby tube station, where she just misses a train. Then a service delay is announced, so Helen heads for the street to hail a cab. Instead, she tangles with a mugger who cuts her forehead, and she’s taken to the hospital.

This sequence is intercut with another one: Inhabiting an alternate reality, another Helen catches the train, where she sits next to James (John Hannah, Four Weddings and a Funeral’s eulogist). Helen 2 soon arrives home, where she finds her unemployed novelist boyfriend Gerry (Irish-film regular John Lynch) in bed with old flame Lydia (Jeanne Tripplehorn). Helen 2 leaves Gerry, moves in with her pal Anna (Zara Turner), runs into James again, and cuts and lightens her hair, so she can be easily distinguished from Helen 1.

When Helen 1 arrives home from the hospital, Lydia has already left; it will be months before Helen 1 realizes that Gerry is cheating on her. Meanwhile, she works crummy delivery and waitressing jobs while Gerry continues to dither with his novel and dally with the overbearing (and unbearably American) Lydia. In that time, Helen 2 has been inspired by James to start her own PR agency, has fallen in love with him, and is living a much more glamorous (and, frankly, blonder) life. Helen 2 still faces one more predicament, but it’s pointless and apparently contrived just so she and James can have a romantic breakthrough in the rain. Then Helens 1 and 2 (almost) meet again, tying up the plot.

Fractured consciousness and split identity are longtime modernist obsessions, explored in films like Resnais’ Je T’Aime, Je T’Aime (in which a time traveler gets lost in his own ambiguous past) and Buñuel’s That Obscure Object of Desire (in which a bewitching woman is actually played by two actresses). Howitt, an actor making his feature-directing debut, merely manages to shoehorn these provocative concepts into a tidy sitcom. Paltrow may have the best British accent of any young American actress, but Sliding Doors isn’t half so audacious as Emma—which was hardly an experimental film.

Perhaps abashed that he cast a Yank as the lead in a film that glamorizes booming London, Howitt weighs Paltrow down with lots of self-conscious British slang: Helen is forever uttering various forms of “shag” or “wank.” He also casts himself in a small part and throws in a reference to Menlove Avenue (John Lennon’s boyhood address, which is not in London).

Such inside jokes provide little distraction from Howitt’s cool-Britannia scenario, in which Americans are arrogant, Irishmen are losers, and London is a just plain adorable place to fall in love or dine out. (We know the latter because Helen does the publicity for gala openings of hot new restaurants.) Those who are partial to London (or Paltrow or Hannah) may very well be charmed. But Sliding Doors does leave one grave question unanswered: If London is so cool, why is the film’s soundtrack so lame?

Both terminally old-fashioned and smarmily up-to-date, David Mamet’s latest con job, The Spanish Prisoner, is a joke at the expense of naive corporate underling Joe—but also you, dear viewer. The writer-director wants to play both for chumps, but he forgets that real people aren’t as easily fooled as his own literary creations. Mamet is so delighted to flaunt his own machinations that he eliminates the possibility that any savvy filmgoer will believe them.

In the film’s opening sequence, Joe Ross (Campbell Scott) and several co-workers arrive on a Caribbean island, where they are archly scrutinized by airport security devices. Joe is there to explain “the process” to his boss Klein (Ben Gazzara) and some other corporate bigwigs—but not to us. Mamet never reveals this corporate secret, not even what kind of process it is; when Joe writes an estimate of how much money the procedure will yield the company, Mamet’s camera is coyly deployed on the wrong side of the blackboard. The gag, apparently, is that all the film’s bother is about nothing. But that gag doesn’t play the way it’s supposed to.

While on the island, Joe meets Jimmy Dell (Steve Martin), a purportedly wealthy businessmen who shows an inordinate interest in introducing Joe to his lawyer (so Joe can renegotiate his deal with the company that owes him so much for whatever) as well as his beautiful sister. Joe also spends some time with his friend George Lang (Mamet crony Ricky Jay) and the company’s new hire Susan Ricci (Rebecca Pidgeon, Mamet’s wife); the latter acts—if you call it acting—like an ironic update of the plucky Girl Friday from a ’30s screwball comedy. (Imagine a cross between a Valley girl and Jennifer Jason Leigh in The Hudsucker Proxy and you’ll have some idea how annoying Pidgeon is.)

Do all these people mean to steal “the process” and shamelessly manipulate Joe just for their own (or Mamet’s) pleasure? Enough of them do, and they do so at great length. If the simplest sting is best, then this one is a disaster. It involves more tricks and more collaborators than could possibly be necessary and relies primarily on the fact that Joe is just too dumb to live. He follows the con artists’ script as if it were, well, a script, and when asked for something that will demonstrate his innocence, he can’t even remember that he has it. (At this point, the movie becomes the college-educated equivalent of one of those slasher movies where the victim heads directly for the place most likely to harbor a knife-wielding psychopath.) Eventually, a previously unintroduced character steps in to explain the rest of the labored plot.

Unlike a lot of Mamet’s work, the film isn’t fueled by profane, manly chatter. Most of the characters are supposed to be smooth—and Martin and Gazzara actually are—or ostentatiously innocent. (Susan even exclaims “Crikey!” at one point.) The script, however, is both gawky and knowing. Named after a venerable con game, The Spanish Prisoner is not likely to dupe anyone.CP