1920. Harihar, Sarbajaya and their ten-year-old son Apu, live in the Temple City of Banaras (Varanasi) on the banks of the holy river Ganga (Ganges). Harihar earns a meager living by reciting religious scriptures. The film opens with Apu wandering and exploring the city. He also encounters their neighbor Nanda Babu, who would soon make a pass at Sarbajaya.

Harihar falls ill with fever and collapses at the riverbank. In the early hours of the next morning, Sarbajaya wakes Apu to fetch holy water from the river to put in his father's mouth as he is dying. Harihar's death leaves mother and son to fend for themselves.

The mother decides to return with Apu to live in a village where an old uncle works as a priest. Apu's mother works to support the family. Apu is initiated into priesthood and takes over the old man's work. He is unhappy because he wants to go to school. Apu persuades his mother to send him to school. She makes sacrifices so that he might pursue his studies.

Apu, now sixteen, wins a scholarship and departs for Calcutta, leaving her alone. It breaks Sarbajaya's heart, but she relents. Her health is failing, and the loneliness in the village takes its toll.

Engulfed in city life - studying during the day and working in a printing press at night to pay for his expenses - Apu grows away from his mother. His visits get shorter as the time passes. This emotional distance unnoticed by the growing Apu, hurts Sarbajaya deeply. She waits silently for her son's visit as her illness accelerates and falls into a depression.

On a night sparkling with dancing fireflies, Sarbajaya dies. Apu comes back to an empty house. He grieves for his mother, but soon finds strength to leaves the village for the last time, to carry on with his new life in the city ...

Aparajito is the second film in "The Apu Trilogy", preceded by Pather Panchali and followed by Apur Sansar. The film is basically about Apu growing up and growing away from his mother. The highlight of the film is the mother-son relationship and conflict. The characterization of Apu and mother are a treat. Karuna Banerjee gives a brilliant performance as Sarbajaya.

As usual, the film is devoid of excesses both in form and content. The two deaths, of Harihar and Sarbajaya, are handled with great elegance.

At dawn Harihar lies ill with Sarbajaya sitting beside him though the night. He mumbles, "Ganga". He is asking for a sip of holy water from the river 'Ganga'. Sarbajaya wakes Apu to fetch water from the holy river. Apu brings the water. Sarbajaya lifts Harihar's head and pours the water in his mouth. Harihar's head drops back on the pillow. Cut to a shot of a flock of pigeons taking off and whirling in the sky. Harihar has been freed of his misery.

In the sequence of Sarbajaya's death - Evening, Sarbajaya is sitting leaning against a tree outside her house, awaiting Apu's return. A train passes but she does not react, as she knows Apu is not on this train. Next, we see her sitting in the verandah of the house, expressionless. Suddenly, she hears Apu calling her. She is hallucinating. Hoping that Apu has returned, she drags herself out. As she stands looking for Apu, she sees a group of fireflies swirling by the pond.

Filming of this scene posed a technical challenge, as even the fastest available film stock could not capture the light emitted by the fireflies. Ray and his crew overcame the problem with an indigenous solution. Ray recounts in his 'My Years with Apu', "... We chose the toughest members of our crew, had them dressed up in black shirt and trousers and let each of them carry a flashlight bulb and a length of wire and a battery. The bulbs were held aloft in their right hands while they illustrated the swirling movements of fireflies in a dance, alternately connecting and disconnecting the wire to the bulbs ..."