After eight years of close collaboration with her supervisor, Mathilde suddenly finds herself inexplicably victim of moral harassment by him. In parallel, Thibault has just split up with his girlfriend after a frustrating two-year relationship where they exchanged very little. Mathilde and Thibault have never met, they are just two figures among millions of others. Two people who may bump into each other or who may merely pass each other by. But one day in September, their paths meet.

A 30-year-old American woman enters a teenage party in the South of France. Some of the guests wonder who she is and what she is doing there.

One hot afternoon in the south of France, several paths are converging towards a tragic conclusion. Those involved are: Stéphane and Luigi, two cousins who have just emerged from adolescence; Georges, a retired old man; Amélie, Luigi’s girlfriend; and Amélie’s mother Anne. Little do they know how their lives, scarred by fear, humiliation and weariness, will become intertwined and propel them to a terrible outcome...

How do you ask a wild, impetuous hairdresser on a date if you're a pathologically timid philosophy student with no social skills?