Charles Hauffman, played by Dany Boon, is a hardworking taxi driver based in Paris who finds himself in a precarious financial position. Struggling with mounting debts and facing the very real possibility of losing his professional driving license, Charles is desperate for a turning point. This arrives in the form of a request to pick up a client named Madeleine Keller, played by Line Renaud in her elder years.
The 92-year-old Madeleine needs transportation from Bry-sur-Marne to a retirement home located in Courbevoie. Interestingly, the instructions for the trip are unusual, as Charles is told to begin the meter reading immediately, even before he has officially arrived at the pickup location in Bry-sur-Marne. However, once they are together, Madeleine requests a detour. Rather than taking the direct route to the retirement facility, she asks Charles to drive her around the city of Paris, visiting various locations that have held deep personal significance throughout her long and tumultuous life.
As they traverse the city, the journey becomes a gateway into Madeleine's past. She reflects on her youth, played by Alice Isaaz, specifically recalling a clandestine affair she had with an American soldier during World War II. This brief but impactful relationship resulted in the birth of her son, Mathieu. As an adult, Thomas Alden portrays the son, who grew up as a photojournalist harboring deep resentment toward his mother for her long absence and imprisonment.
The narrative delves into the darker chapters of Madeleine's life, focusing on her marriage to Raymond Haguenot, also known as Ray, played by Jérémie Laheurte. Their union was far from happy, as Ray exhibited violent and abusive behavior toward her. Because of the legal constraints of the time, Madeleine found herself unable to obtain a divorce on the grounds of domestic abuse. Driven to a breaking point by the relentless torment, she eventually took violent retaliatory action that left Ray maimed. This act of desperation led to criminal proceedings and a lengthy prison sentence, presided over by the court president, Christophe Rossignon. Ironically, her imprisonment became a cause célèbre, sparking a national conversation and fighting for the marital rights of French women.
Throughout the cab ride, the interaction between the driver and his passenger is marked by several quirky and touching incidents. At one point, they cause a significant disruption in traffic just so that Madeleine can use the restroom at a restaurant run by a manager played by Sylvie Audcoeur. In another instance, Charles commits a traffic violation that threatens his already fragile business license, but Madeleine uses her wit and influence to help extricate him from the situation.
Their journey is a tapestry of history, as Madeleine recalls her experiences during the May 68 demonstrations and the geopolitical tension of the Vietnam War. They visit somber landmarks, including a memorial dedicated to the Parisians who were deported during the Second World War. Along the way, they share a meal and a growing bond of mutual respect.
By the time they finally arrive at the retirement home—where we meet the director Alexandra Mercouroff and staff members such as the nurse Tom Hudson and the maintenance agent Christian Mupondo—Charles is so deeply moved and engrossed by Madeleine's life story that he neglects to collect his fare. Shortly after the trip concludes, the narrative closes with a final communication delivered to Charles by Madeleine's barrister, serving as a poignant conclusion to their unexpected connection.
