At the hospital, three brothers meet at the bedside of their mother in a coma. To pass the time, they discuss the merits and pleasures of marital fidelity and infidelity. The conversations of the two youngest advance as the days go by in increasingly juicy details and fantasies, which will push them to act against the morals and more solid values ​​of the eldest.

Gilda Bessé shares her Paris apartment with an Irish schoolteacher, Guy Malyon, and Mia, a refugee from Spain. As the world drifts toward war, Gilda defiantly pursues her hedonistic lifestyle and her burgeoning career as a photographer. But Guy and Mia feel impelled to join the fight against fascism, and the three friends are separated.