César runs a bar along Marseilles' port, assisted by his 23-year-old son, Marius. Friends since childhood, Fanny and Marius love each other, but Marius has a secret wanderlust: every ship's whistle stirs a longing for foreign lands. When M. Panisse seeks Fanny's hand in marriage and when a departing clipper needs a deckhand, Marius and Fanny must decide who and what they love most. César, with his generous, wise spirit, tries to guide his son.

Soon after Marius's departure, Fanny learns that she is pregnant with his child, to the disappointment of her mother and of Marius's father, César. To secure a better life for her unborn child, she accepts a marriage proposal from the aging widower Honoré Panisse.

Leaping forward twenty years, the trilo'gy continues with the death of Fanny's husband, Panisse, and the discovery of her secret by her son, Césariot. The young man resolves to track down his biological father, Marius, whose life has been fraught with calamity and poverty.