The plot of the series focuses on Marco, a boy who lives with his family in the harbor city of Genoa, Italy during a depression period in 1881. Marco's father, Pietro Rossi, is a manager of a hospital who dedicates his time to treating poor patients, and therefore the family has financial difficulties. His beloved mother, Anna Rossi, goes to Argentina to work as a maid to earn money for Marco. When the letters from his mother stop coming after an indication that she is sick, Marco fears the worst for her fate. Since his father is too busy working in his clinic and his older brother Tonio was sent to train as a locomotive driver in Milano, he is the only one free to go search for her.