A little boy, all the more passionate about trains as he is the stationmaster's son, is fascinated by a wonderful locomotive, the mighty elegant Pacific 232 that he sees every day. At one point, he manages to ask Monsieur Martin, its engineer, questions about him and how he became what he is now. The man tells him everything, from his being born to an alcoholic rag man to his being an apprentice to his becoming the operator of a switch locomotive first, then of a slow train, then of an express train, then of a luxury train named The Silver Arrow. But the apotheosis, he tells the kid, came with the 232. Unfortunately, says Martin to the enthralled boy, he has now attained the ceiling age and he is, whether he likes it or not, going to say farewell to this hard but exciting life...