On December 23, the holiday season is in full force and the destinies of strangers intertwine: a hardened bachelor wants to find love; a couple expect their first child; a singer returns to the stage after a break; a mother tries to organize the perfect Christmas; a teen carries a big secret; a man struggles with the modern world; and the new manager of a large hotel must prove her worth.

Back in the 1970s, we see a young Louise who is crazy in love with Vincent, a rebellious activist. Along the way, Louise will have to give up some of her political ideals and make some difficult sacrifices. Today, Louise has become a formidable businesswoman at the head of Nocturne, her perfume empire that owes much of its success to her top-selling perfume Nuit Blanche. Everything changes when, at an evening reception celebrating her success, Louise dies alone in her garden. Is it murder or an accident?