After Mia auditions for the lead role for a movie that is going to be shot in Paris, we now see across the screen that it is winter again- only five years have passed since that audition. We see that Mia is now a famous actress, going back to that coffee shop she used to work at, and Sebastian is now the owner of his jazz club he's always wanted. Mia drives up to her house, and we find out that she is married to another man and has a baby girl. Sebastian is also single and lives in a new apartment.
Mia and her husband then go out to dinner, leaving their baby girl with a babysitter. They are on their way to a movie and dinner event but get stuck in traffic. She then asks him if he wants to pull over and just go to dinner, which he happily agrees to. We then see them walking on the sidewalk after finishing dinner. As Mia is about to get in the car, her husband asks her if she wants to check out this club that looks pretty cool to him. She agrees. As they walk into the club, we find out that it is Sebastian's club. Mia and her husband sit down just as the band performing is finishing. Sebastian walks onto the stage and after introducing the band to the audience spots Mia in the crowd. They stare.
As Sebastian is getting ready to play, he murmurs "Welcome to Seb's." He then starts to play on the piano "Mia & Sebastian's theme." As the song gets faster, the screen goes to the scene when Mia first met Sebastian in that restaurant on Christmas at the beginning of the movie. We see the sequence when Sebastian is getting let go by the manager, and Mia starts to walk to Sebastian as he is leaving, again. Only instead of Sebastian hitting Mia on the way out, he kisses her. All of a sudden, the people in the restaurant start to get up and dance. We are then watching a sequence of Mia and Sebastian living their life together as if they ended up with each other while all of the different songs are playing in the background in a medley. Throughout the sequence, we see scenes that were in the movie already, like Mia auditioning for the lead role. We also see some "dream" sequences, like Mia and Sebastian dancing behind a movie background.
As the piano version of "City Of Stars" starts to play in the background, we see a sequence of Mia and Sebastian with their little baby boy, growing up before us, again as if they ended up together. As the music starts to slow down, we see the exact same scenes as we watched before with Mia and her husband leaving the house, getting stuck in traffic, and going to the jazz club only this time, with Sebastian. Mia and Sebastian are in the club, watching the pianist, then start to kiss. We then hear the final note being played as Sebastian looks up. This whole big sequence was a fantasy. The audience starts to clap as Mia and her husband gets up and leave. As Mia walks to the door, she stops and looks at Sebastian on the stage. They both nod and smile at each other. Mia then leaves and Sebastian starts to play again.