Paris, winter, 1999. Fifteen-year-old Camille and 19-year-old Sullivan are passionately in love with each other. However Sullivan wants to go to South American for a year and this prospect leaves Camille feeling desperate. Sullivan leaves at the end of summer and, after a few months, stops writing to Camille, who tries to kill herself in the spring.
2003. Camille focuses on her architecture studies. She meets a famous architect, Lorenz, who nutures her self-confidence. She falls in love with him.
2007. Camille and Lorenz are a stable couple. Camille is his assistant, but she soon feels capable of establishing her own agency. It is at this point that she once again crosses paths with Sullivan. Despite a cool first meeting, Camille sees him a second time and eventually gets back together with him. She has never stopped loving him; he becomes her lover. Her heart is now torn between two loves.