Pietro Rossi, father to Marco and older brother of Tonio, manages a charity hospital in Genoa, Italy, during the economic depression of 1881. His dedication to treating impoverished patients plunges the family into significant financial hardship. This strain forces his wife, Anna Rossi, to seek employment in Argentina. Pietro remains in Genoa, committed to his medical work. When Anna's letters cease, suggesting possible illness, Pietro faces mounting pressure from his son Marco to act, yet seems indecisive about investigating her situation.

This period strains Pietro's relationship with Marco. Pietro persists in viewing Marco as a child, excluding him from major decisions, which frustrates Marco. This tension escalates into conflict, with Marco developing unconscious resentment toward Pietro for not emigrating instead of Anna. After Marco secretly secures work to fund a journey to Argentina and later attempts to stow away on a ship, Pietro initially refuses to support the plan.

However, Marco's attempted stowaway forces a confrontation. This event prompts a change in Pietro; he recognizes Marco's determination and maturity, ultimately consenting to his journey to search for Anna. Pietro provides Marco with the necessary travel documentation and permission. He stays in Genoa during Marco's journey across South America.

Following Marco's successful reunion with Anna and her recovery, Pietro is reunited with both upon their return to Genoa, restoring the family. Pietro primarily serves as the catalyst for the family's financial predicament and Marco's journey, embodying the struggle of maintaining professional dedication amidst familial sacrifice. His character development centers on shifting from paternal authority to acknowledging his son's autonomy.