Albie Hay’s review published on Letterboxd:
Before Midnight picks up Jesse and Celine a further nine years on from where we left them. They've become a couple, raising two daughters and living in Paris. On holiday in Greece, their seemingly steady relationship begins to burst at the seams. He wants to move to America to be closer to his son Henry, while she has her eye on a new job offer. This disagreement brings latent disappointments, distrusts and regrets to the fore and, faced with a situation that could potentially ruin what they've built together, they have to sort out their priorities, and fast.
What makes the Before trilogy work so well is the mere fact that we believe it. By leaving gaps of nine years, we as audience members are presented with enough time for these characters to change significantly, but not enough for us to be unable to accept them as the same people all the way through. Their passage from hedonistic and youthful romantics to slightly less hedonistic and youthful romantics to jaded people who are in the process of reflecting on their time together is completely convincing, and this is because Ethan Hawke and Julie Delpy completely vanish into their roles, making everything that comes out of their mouth sound thoroughly natural. The fact that they collaborated on the screenplay with director Linklater is no surprise, since they have come to understand the rhythms of their characters so well.
While the film is very occasionally wearisome and leaves us with a mixture of tastes in the mouth, it's consistently funny and truthful so that we're never in doubt of the talent of everyone involved in making it. The locations are stunning to boot.