When we last glimpsed Jesse and Celine, the chatty young lovebirds in Richard Linklater's beguiling backpacker romance “Before Sunrise” (1995), they had just parted ways on a train platform in Vienna, concluding a whirlwind evening in which they met, fell in love and promised to meet again, six months later, at the very spot of separation. Kiss, wave, fade to black.

Did Jesse and Celine make good on their promise? We could only speculate, and that's what made Linklater's open- ended denouement so novel. Like the proverbial half-full glass of water, it forced the audience to reflexively examine its own sensibilities: Pessimist or optimist? Cynic or romantic?

Score one for the cynics. Kind of. In “Before Sunset,” a floating, richly felt talkathon that picks up nine years after their last farewell, we find out that Jesse and Celine never did make their second date in Vienna. Still, that doesn't stop the erstwhile lovers from once again embarking on an irresistible tango of courtship and wordplay that proves just as romantic — in its own, jaded, thirtysomething way — as the first.

Like its predecessor, “Before Sunset” is a marvel of conversational form, essentially a one-act monument to gab. Jesse, played by a gaunt, handsomely grizzled Ethan Hawke (“Taking Lives”), is visiting Paris on the last leg of a European press tour in support of his new novel, which he secretly based on his one-night romance with the brainy French grad student, Celine. When Celine shows up at the book store — fulfilling Jesse's fondest subconscious wish, we later learn — the two take a stroll. It will be a brief visit: Jesse needs to leave for the airport in 70 minutes to make his flight back to America.

First they figure out why their second date in Vienna never happened. Then they talk some politics (Celine has sprouted a robust anti-globalism streak, surprise, surprise). They exchange ideas about sex and careers, and launch into deep-dish musings on the nature of desire and identity. Finding ways to extend their visit, they confess feelings of isolation, romantic frustration and emotional paralysis. Both are entangled; neither is happy.

Co-scripted by Linklater and the actors themselves, “Before Sunset” has wonderfully organic moments when Hawke and Delpy incorporate pieces of themselves into the characters. In one scene, Celine teases Jesse about a thought-crease that runs between his eyebrows. In another, she performs a pretty guitar waltz written by the actress herself. Even the fact that Hawke is playing a writer seems less designed to flatter his own, very real literary pretenses than it is an honest attempt to enrich the character.

It should be stressed that this movie takes place in Paris at dusk, as good a time and place for any two people to rekindle a long-dormant affair. Bathed in caramel sunset hues, Jesse and Celine float down the Seine and trade anecdotes about Notre Dame, arriving once again at a moment of supreme romantic well-being. As before, we're not sure if it's true love or fleeting infatuation, but in nine or 10 years, maybe we'll get the answer.

Before Sunset
Starring: Ethan Hawke, Julie Delpy
Rating: R (profanity, sexual references)
Running time: 80 min.
Grade: A-