Un étrange voyage is a 1981 French drama film directed by Alain Cavalier, starring Jean Rochefort and writer/filmmaker Camille de Casabianca.
Pierre, in Paris on his own in his forties and working as a picture restorer, has little contact with his daughter Amélie, a student who he supports, and none with his ex-wife Claire.
His closest relationship is with his 80-year-old widowed mother, still active in her house in Troyes, who telephones to say she is taking a train that afternoon to visit him.
Amélie, on vacation after doing well in her exams, agrees with his reasoning and the two get permission from the railway company to search the 150 kilometres of track.
Knowing now the emotional fragility of her father, she gets him to take her for a good dinner with lots of wine and, once he is relaxed with a pretty young woman, breaks the news to him.