Love on the Run (1979) on Netflix

Plot summary

Colette, a defense lawyer, spots Antoine Doinel leaving the courthouse where his divorce from Christine is finalized. Curious, she visits a bookstore to buy the semi-autobiographical novel he published; the shop belongs to Xavier, her boyfriend, whose feelings for her she cannot read. On the same day Colette boards a train to Aix-en-Provence for a court case, while Antoine is at the Gare de Lyon to see off his son Alphonse, who leaves for a summer music camp. A phone call to Sabine, the record shop clerk he is dating, ends in a quarrel over his secrecy, and when Antoine catches sight of Colette he jumps aboard her train.