Plot
In 1946, Antonietta, an impoverished single mother, arranges for her son Amerigo to travel from Naples to northern Italy to live with a host family as part of the treni della felicità (trains of happiness) initiative organized by the Italian Communist Party to transport poor southern Italian children to northern families who could support them in the years after World War II. Amerigo refuses to go, but relents he is caught by Antonietta's boyfriend fraudulently selling white-painted rats for furs. At the station, an elderly woman scares the children and their parents from sending the children up north, claiming that they would be deported to Siberia and eaten by cannibals, but the PCI cadres harangue the crowd with the dire state of their children following the war, overcoming resistance to the trip.
Arriving in Modena, the children are picked up one-by-one by their respective fosters, with Amerigo, the last to be fostered, reluctantly being taken in at the last-minute by Derna, a former partisan who lives alone after losing her boyfriend during the war. The next day, Derna introduces Amerigo to her brother Alcide and his sons Revo, Lucio and Nario. Alcide teaches Amerigo multiple skills including the playing the violin, which Amerigo takes up a passion for. At the same time, Amerigo comes into conflict with Lucio, who is jealous of his father's affections towards Amerigo. When Alcide's household invites Amerigo to try baking bread in the oven, Amerigo, recalling the old woman's scaremongering, hides in the woods until Derna promises that he will go home at the end of the wheat harvest, leading to them gradually opening up to each other.
Amerigo attends school, where he is bullied for his being a southerner while being defended by a reluctant Lucio. At a May Day festival, Lucio taunts Amerigo about his mother, leading to Amerigo beating him up before running away. He then stumbles across Derna being struck by a chauvinist colleague. Later that night, Amerigo compares Derna with his mother, saying that Antonietta would not have let herself be treated that way before comforting her as she collapses into tears. The next evening, a desperate Lucio seeks help from Amerigo in finding Rossana, a homesick girl from the south who ran away after Lucio told her to follow the railway tracks home. They find Rossana by the tracks next to a skeleton that she discovered earlier. Lucio finally becomes friends with the two.
The harvest arrives and the southern children are sent home. Amerigo is greeted coldly by his mother, who cynically tells him that he is ordained for a destitute life. After some time, Amerigo, who is the only child not to receive messages and gifts from his fosters up north, visits the PCI offices and learns that his mother had kept Derna's packages from him. Arriving home, Antonietta reveals that she had pawned the violin Amerigo received from Alcide. When Amerigo reproaches her for being selfish, Antonietta slaps him. That evening, Amerigo runs away and takes a train to Modena, where he is tearfully reunited with Derna.
In 1994, an adult Amerigo, who is now a successful violinist, is informed of Antonietta's death. Arriving in Naples, he discovers his old violin which Antonietta had redeemed, sending him into tears. A voiceover reveals that Antonietta had actually allowed Amerigo to run away and had written Derna asking her to accept Amerigo permanently or send him back, saying that those who let others go love them more than those who keep them.
