Prabhakaran, commonly known as Prabha, is an ambitious graduate with a passion for rocket science who finds himself driving an auto-rickshaw in Chennai because finances won’t let him pursue his dreams. He carries a quiet resentment toward his father for the life he couldn’t give him and feels the weight of everyday injustices as he navigates a world that seems to deny his ambitions. His best friend, Kamala, is a traffic constable who sees the human side of the city’s bustle, offering a steadying presence as Prabha carries a growing sense of frustration about his stalled future.
One fateful day, Prabha’s life takes an extraordinary turn when a young boy asks for a ride to Madras University, and the boy turns out to be APJ Abdul Kalam in a time-twisted moment from 1948 into 2023. Kamala is skeptical of the claim, while Prabha seeks out his professor in the hope of a rational explanation, only to be met with a firm rejection of time travel as a real phenomenon. The young Kalam recounts a backstory involving a letter from a Dean, Mr. Arivazhagan, that set in motion a journey that lands him in Madras, where he first crosses paths with Prabha.
Determined to help Kalam return to his home in [Rameswaram], Prabha arranges a bus ticket for the young scientist. Yet Kalam asks him to accompany him, and Prabha agrees. Their shared odyssey leads them to new ground—and a set of questions they hadn’t anticipated. In Rameswaram, Prabha shows Kalam books outlining Kalam’s future publications, but the younger man cannot recognize them. After a screening of a horror movie, a candid conversation makes them wonder if Kalam’s time leap is rooted in personal reasons, while Prabha counters that Kalam’s life has always been about national service rather than personal gain.
The journey brings Kalam into contact with his childhood friend, Sastri, now an elderly man who initially fears that the boy is a ghost. Once the truth sinks in, Sastri guides them to Kalam’s childhood home, and there they uncover a diary from 2015—a discovery that Prabha had already glimpsed in his dreams. The diary mentions Annachi, a local shop owner who was close to Kalam and Sastri in their youth, and Kalam’s lingering debt to him—one anna. Kalam’s fixation on returning that small sum unsettles Prabha, who argues that Kalam must travel for a larger, more meaningful purpose. Before Kalam’s niece can uncover the truth, the trio escapes, and Prabha resolves to help Kalam finish what he started by returning the one anna.
Their search for Annachi’s living heirs leads them to Savarimuthu, a distant relative who is intent on suicide after a heated quarrel with his wife. The sight of Prabha and Kalam spurs Savarimuthu to jump into the sea, and Prabha dives in to pull him to safety. With that act, Kalam’s debt is deemed settled. Yet even as Kalam believes his time travel may come to an end, Prabha remains wary. Then the astonishing moment arrives: the bus Kalam boarded in 1948 reappears before them, confirming that Kalam’s stories were not mere fables. The younger scientist explains that the journey was driven by a desire to cherish the small, precious memories of life. His diary reveals a wish to repay that one anna on the last day of his life and acknowledges that Prabha’s selfless act—helping a 14-year-old boy reach home safely—may count as a greater triumph than his own rocket innovations.
With those parting words, the young Abdul Kalam departs, and the world Prabha knows begins to shift. The experience softens him, making him more courteous and grateful toward the father who sacrificed so much to provide for him. The film closes on a note of quiet transformation: a young man who once felt trapped by circumstance learns to value the small moments, the debts repaid, and the family ties that shape a life devoted to service.
