A Parisian family ventures to the countryside for a leisurely Sunday outing. The group comprises a mother, father, their daughter Henriette, and her suitor Anatole. Seeking respite from their urban existence, they settle near the Seine River for a picnic. As they lounge, two local men, Henri and Rodolphe, spot the family and are particularly captivated by Henriette's beauty. The men casually approach them and engage in conversation, eventually charming the family into a relaxed state of friendliness. They offer to take Henriette and her mother boating while the father and Anatole go fishing. Eager for a bit of adventure, the women agree, resulting in an afternoon split between the contrasting interests of leisure and budding romantic curiosity.

The serene flow of the Seine and the idyllic countryside become settings for intimate connections. Henriette, separated from her family, shares a few moments with Henri, which spark mutual attraction. Their brief time together leaves an indelible mark on both their hearts. The day unfolds with lightheartedness and wistful undercurrents, casting a nostalgic hue over the simple pleasures of the rural retreat. As the shadows lengthen and the day draws to a close, unspoken emotions linger in the air. The family's return to Paris symbolizes a departure from the transient enchantment of their countryside day, underscoring themes of fleeting joy and the complexities of human connections.