Paris 1942. François Mercier is an ordinary man who only aspires to start a family with the woman he loves, Blanche. He is also the employee of a talented jeweler, Mr. Haffmann. But faced with the German occupation, the two men will have no other choice but to conclude an agreement whose consequences, over the months, will upset the fate of our three characters.

To spice up a dinner party, old friends agree to share every private message that pops up on their phones -- with disastrous results.