Camille returns from a business trip. Young and rich heiress of a cosmetics company, Cosmos, which she has taken over since the death of her father, she discovers that Vincent, the man who shares his life, took advantage of his absence to leave and move his business without even leaving him a word of farewell. Determined to win back her former lover, she finds an unexpected ally in the person of Zac, Lena's betrayed fiancé, whom she met fortuitously at the Bois de Boulogne, while both were in the process of to spy on their ex. Zac is a broke writer, lacking inspiration: they make common cause to recover their lost loves ...