The successful novelist Judith Ralitzer is interrogated in the police station about the disappearance of her ghost-writer. A serial-killer escapes from a prison in Paris. A missing school teacher leaves his wife and children. In the road, the annoying and stressed hairdresser Hughette is left in a gas station by her fiancé Paul while driving to the poor farm of her family in the country. A mysterious man offers a ride to her and she invites him to assume the identity of Paul during 24 hours to not disappoint her mother. Who might be the unknown man and what is real and what is fiction?

The Tunisian born hero of the film decides to break with his disorganized yet habit-ridden life in Paris, and sets off to discover his homeland, which he left at 6 years old, and to rekindle the memory of his mother, who died when he was a child.

A jaded and charming police inspector is assigned along with his cheerful partner to a case involving the mysterious death and/or suicide of a wealthy entrepreneur. The chief suspect is his enchanting wife who was aware that her husband had a mistress. It is also possible that the dead man may be the victim of a radical terrorist group.

The film follows four families, with different nationalities (French, German, Russian and American) but with the same passion for music, from the 1930s to the 1960s. The various story lines cross each other time and again in different places and times, with their own theme scores that evolve as time passes. The main event in the film is the Second World War, which throws the stories of the four musical families together and mixes their fates. Although all characters are fictional, many of them are loosely based on historical musical icons (Édith Piaf, Josephine Baker, Herbert von Karajan, Glenn Miller, Rudolf Nureyev, etc.) The Boléro dance sequence at the end brings all the threads together.

The film follows the exploits of Jacques, a car-mechanic turned pro-thief, and his Jewish co-conspirator Simon as their robberies, beginning well before the Second World War, take on a political coloration under the occupation.

In WWII France, poor and illiterate Henri Fortin is introduced to Victor Hugo's classic novel Les Misérables and begins to see parallels between the book and his own life.

The plot is about a trial against three men who tried to earn loads of money by illegal methods to get to Canada and about the lawyers and the judge who get on with the trial and who are being unfaithful to their couples.

2015 film