"Before Midnight."
"Before Midnight."
Warning: This review contains mild spoilers about the fate of characters from earlier entries in the series.

With "Before Midnight," Richard Linklater has completed one of the finest movie trilogies of all time. Nearly 20 years have passed since Jesse (Ethan Hawke) and Céline (Julie Delpy) met on a train in Vienna and spent a passionate night together in "Before Sunrise," then abruptly parted ways, only to tentatively pick up where they left off nine years later with "Before Sunset." That movie ended without resolving a tantalizing possibility: Would Jesse, now a successful writer stuck in a dead-end marriage, truly miss his flight back home and spend more quality time with Céline? "Before Midnight" answers that question while asking many more, consolidating the full power of the earlier movies into a masterful treatise on the evolution of romance.

The simple answer is yes: Jesse missed his plane. Nearly a decade later, he's still dealing with the aftermath. But nothing is ever simple with these movies, least of all the fate of its characters. In the opening minutes, Jesse bids farewell to his 14-year-old son, who continues to live with Jesse's ex-wife in Chicago and just completed a vacation with his father in Greece. Jesse says goodbye, exits the airport and walks to his car…where Céline awaits alongside their twin daughters. After two decades, the couple has at last satisfied the fantasy of forming the life together that always eluded them in the earlier movies. Having established that much, "Before Sunset" dives headlong into determining whether it was worth the wait -- and once again avoids a firm conclusion.

Nobody geeks out over the trivia of this franchise better than the fictional creations who lived through it, but even they can't predict what comes next.

After its surprising prologue, "Before Midnight" launches into the same observational formula that has become the series' trademark. In the first of many sustained takes, Jesse and Céline drive across the Greek countryside while discussing matters large and small, bringing us up to speed in the process. Still a successful novelist, Jesse bemoans the distance between him and his son during his final years at home, while workaholic Céline debates whether she should take on a new job opportunity in Europe.

By this point, their witty, contemplative banter has evolved into mature analysis of their joint responsibilities, with Céline jokingly asserting that Jesse's parenting guilt bodes poorly for the survival of their marriage. "The world is fucked," she sighs, providing the first indication that the couple faces a number of insecurities beyond their immediate future together. It's not clear yet whether she's entirely playing around, which provides the first indication of how the free-flowing nuances of Céline and Jesse's conversations lend themselves to interpretation.

This initial prolonged exchange segues into the next wave of discussion, yet another scene-setter that helps situate Céline and Julie in the present. Finishing up a vacation at their friend's house by the beach, they gather at a lunch table with several other couples (including characters played by Greek cinema notables Ariane Labed and "Attenberg" director Athina Rachel Tsangari, the latter in an enjoyably smarmy bit). Speaking candidly about the nature of lasting romance, they debate the specifics of their history together.

A canny move by the filmmakers, this extended sequence recounts the events of the earlier movies for anyone unfamiliar with them while making it clear that Jesse and Céline have arrived at a stage where they can analyze their progress in greater detail. As with "Before Sunset," Hawke and Delpy share a writing credit with Linklater and firmly inhabit their roles with a naturalistic flow. Nobody geeks out over the trivia of this franchise better than the fictional creations who lived through it, but even they can't predict what comes next.