Before Sunset (15) <br></br> Summer Madness (U)

Haven't I seen you somewhere before?

Only the very naive would imagine that many sequels are motivated by a nostalgic desire to prolong a film's special magic: the only magic most aim to recapture is that of ringing tills. But suppose a sequel were not simply better than the original, but somehow contrived to retrospectively transform the first film? Imagine, for example, if David Lean had reunited Celia Johnson and Trevor Howard a decade after Brief Encounter and allowed their characters another chance at tentative romance over the British Rail teacakes. What if Brief Encounter 2 had been richer and more poignant than the first film? For better or worse, the original would never look the same.

That's essentially what the ever-adventurous Richard Linklater has done in Before Sunset, the follow-up to his 1995 romance Before Sunrise - which was nothing if not Brief Encounter for backpackers. In that film two young students, Jesse from the US (Ethan Hawke) and Céline from Paris (Julie Delpy), enjoyed a whirlwind romance over a single day in Vienna, then vowed to meet there again six months later. Unlike Lean's fatalistic story, Linklater offered the possibility that the couple would keep the appointment and find happiness - and equally, the possibility that they wouldn't.

Well, did they or didn't they? Nine years on, Jesse is in Paris to promote a novel he's written: it's about a couple who have a whirlwind romance and vow to meet again. Asked whether the couple in his book were ever reunited, Jesse insists that's up to the reader: "It's a good test of whether you're a romantic or a cynic," he says wearily, and you suspect it is a question that people have been asking Linklater, Delpy and Hawke for years.

Then in walks Céline. She tells Jesse that she read about the book, put two and two together, and came to say hello. But the former lovers have considerably more to say to each other than that, and take a long walk to get re-acquainted. That's essentially it: they walk and they talk, in leisurely long takes that apparently allow Hawke and Delpy to improvise (they share writing credits with Linklater and Kim Krizan).

At first Céline and Jesse cautiously, affectionately sound each other out, teasing each other about how time has changed them, then opening up in pained confessions of how life took them by surprise. Both look back at their youthful hopes and subsequent disappointments: he is unhappily married with a child, while she, a committed professional environmentalist, has had an eventful but frustrating love life. Both suspect they missed the chance of a lifetime - but are they fooling themselves, or is Linklater fooling us naïve romantics?

The couple's seemingly mundane encounter gains an aura of magic - a sense of being suspended from the contingent flow of life - from the way that events appear to unfold in real time. It somehow feels perfectly normal that this seemingly unbroken passage of emotionally seismic incident should all be contained in a mere 81 minutes, from the initial meeting to the final moment of truth, set to a Nina Simone song. The film inhabits something like the heightened, elastic time that made Linklater's philosophical animation Waking Life (2001) so authentically dreamy. Time seems all the more fluid because it's finite, as the title suggests: the couple have to keep watching the clock, as Jesse must catch a plane home. The question is whether the boundless energies of desire can win out over the constrictions of an airline timetable.

The thrill of reunion is not just between Céline and Jesse: Delpy and Hawke visibly come alive in rediscovering their screen chemistry, which is all the richer now that they're older and can play characters with a few emotional scars. They've aged interestingly: Delpy's former angelic girlishness is hardening around the edges, and she now has a steely hint of brittle wit and severity. And Hawke, once gym-fresh and puppyish, is now gaunt and a little battered: like Jesse, the actor-turned-novelist has himself presumably had too many late nights in a loft scowling over his Powerbook.

Before Sunset ends with perfect grace, leaving us with at the very least a promise of featherlight elation - even though, deep down, its contemplation of missed possibilities is just as melancholic as Flaubert's Sentimental Education. Paris, the literary and filmic capital of lost possibilities, is here not the exotic backdrop we might expect in an American film set in Europe, but the mundane, functional location you'd find in a French one: Linklater shows it as a city made for walking and talking rather than gawping, and the fact that Céline and Jesse barely seem to notice the scenery is a sign of how absorbed they are in each other. It's wonderful to see an American director - and a DoP, Lee Daniel - as comfortable in Paris as, say, Eric Rohmer, and it makes an interesting contrast with the entirely touristic use of Venice in David Lean's Summer Madness, re-released this week in a new print.

Lean's 1955 vehicle for Katharine Hepburn was, in a sense, his own upbeat follow-up to Brief Encounter. Hepburn plays Jane Hudson, a middle-aged single woman from Ohio who visits Europe with vague hopes of romance and finds more than she bargained for in Rossano Brazzi's dashing antique dealer. Co-written by H E Bates, Summer Madness is surprising in that it's very much about sexual rather than strictly romantic desire: there's never any doubt what causes the heroine to tremble with expectation and recoil in terror. But Hepburn's Jane comes across as too ingenuous and too neurotic to be easy company, and there's an awkward theatrical stridency to her performance that really grates.

For all its wry Jamesian dissection of comparative mores, Lean's film looks like a British observer's amused indulgence of the eccentricities of Americans and Europeans alike. Lavishly photographed, the film never quite gets over its appetite for kitsch local colour, and a cast filled out with droll wide-eyed holiday-makers justifies the film's shameless rubbernecking. An early version of the panoramic-postcard cinema of which Lean became the master, this is at once a precursor of A Room With a View and a feelgood variation on the Bette Davis romance Now Voyager, with Camparis instead of cigarettes.

j.romney@independent.co.uk