Grandpa Jehan Daas, an elderly resident of a small village near Antwerp, raises his orphaned grandson Nello following his daughter's death in the Ardennes. Despite advanced age and physical limitations from an old leg injury, Jehan works as a milk cart driver while enduring chronic pain. Their precarious financial situation forces them to live in a modest hut under constant threat of eviction from a demanding landlord who raises their rent.

Initially displaying some gruffness, Jehan reveals profound kindness when he rescues and nurses the abused dog Patrasche back to health at Nello's request, making the dog part of their family. He actively encourages Nello's artistic talents and supports his dreams despite their poverty, serving as both caregiver and mentor. Jehan maintains reasonable expectations for Nello's labor while fostering friendships and positive experiences, such as visits to Nello's friend Alois.

Jehan's character evolves significantly through shared hardships. He transitions from a stern demeanor to openly expressing affection and emotional warmth toward both Nello and Patrasche. His deepening commitment manifests in ongoing sacrifices to provide stability despite relentless economic pressures, solidifying his role as the family's emotional anchor. This continues until his eventual death from old age and declining health. His passing leaves Nello and Patrasche facing immediate eviction and homelessness, precipitating the events that follow.

The narrative consistently frames Jehan through his relationships: as Nello's nurturing guardian encouraging artistic growth, as Patrasche's compassionate rescuer, and as a figure earning community respect through integrity. His legacy persists through Nello's values and the enduring family bond.