Grouchy, obstinate, and self-centered, Professor Isak Borg, played by Victor Sjöström, is a 78-year-old widowed physician specializing in bacteriology. Before this specialization, he worked as a rural general practitioner in Sweden. As he embarks on a lengthy car journey from Stockholm to Lund, Isak prepares to receive the honorary title of Doctor Jubilaris, an acknowledgment of his 50 years since obtaining his doctorate from Lund University. Accompanying him is his pregnant daughter-in-law, Marianne, portrayed by Ingrid Thulin, who harbors resentment towards her father-in-law and is contemplating separation from her husband, Evald, Isak's only son.
During this introspective journey, Isak grapples with feelings of remorse spurred by nightmares, daydreams, and the looming notion of mortality. Along the way, he encounters various hitchhikers, each triggering memories and reflections tied to his tumultuous past. The first to join Isak and Marianne are two young men and their companion, Sara, who bears an uncanny resemblance to Isak’s first love. Reminiscing about his idyllic childhood by the sea, Isak recalls moments spent gathering strawberries with Sara, who ultimately chose to marry his brother. This initial group of travelers continues accompanying them throughout their journey.
Next, Isak and Marianne pick up a bitter couple, the Almans, who narrowly escape a collision with their car. The couple's exchange of vitriol is so intense that Marianne is forced to halt the vehicle, insisting they exit. Their interactions resonate deeply with Isak, reflecting the disappointments of his own marriage. In a poignant dream sequence, Sten Alman confronts Isak, now serving as the examiner, asking him to read "foreign" letters on a blackboard. Unable to do so, Isak watches as Alman deciphers the words: "A doctor's first duty is to ask forgiveness," ultimately concluding, "You are guilty of guilt."
Through these encounters, Isak becomes increasingly aware of his solitude and detachment, recognizing these flaws not only in himself but also in his elderly mother and his estranged middle-aged son. This journey catalyzes a gradual acceptance of his life choices, his current state, and the inevitability of death.
Upon reaching his destination, Isak receives the Doctor Jubilaris title, yet the ceremony feels hollow and devoid of genuine meaning. That evening, he shares a heartfelt farewell with his youthful companions, and in response to a playfully expressed love from one of the girls, whispers, "I'll remember." Later, as he retires for the night in his son's house, a profound sense of tranquility envelops him, giving rise to nostalgic dreams of a family picnic by a serene lake. Ultimately, Isak finds the closure and affirmation of life he has long sought, his face reflecting newfound joy and contentment.
