On 11 October 1943, amid the turmoil of World War II and Japanese bombardments of Madras (now Chennai), the city wakes to a grim discovery. Rajan, [Sivaji Ganesan], a radio engineer and dedicated research man, is found dead in his house in Madras, a self-inflicted gunshot marking the end of his work and life. His neighbour, P. D. Sambandam as Chinnaiah Pillai, had heard the shot and immediately informs the police. The local police inspector, Purushothaman Naidu, arrives to begin the painstaking routine of gathering facts, while a more formal investigation is taken up by C. I. D. officer Sivanandam, Javar Seetharaman, who joins Naidu to sift through the possible motives and suspects.
Naidu leans toward a straightforward thief’s motive—money found at the scene—but Sivanandam objects, noting that the cash and the bank passbook’s withdrawal entry in the same room complicate a simple robbery narrative. Rajan was preparing to leave Madras in the looming shadow of bombings, adding a layer of urgency and secrecy to the case. The investigators move to question five people close to Rajan: his wife Usha, a woman overwhelmed by grief and left unable to speak; Chinnaiah Pillai and Pattabi, Rajan’s younger brother; Hema, Pattabi’s wife; and Ambujam, a dancer involved with Rajan, who is pregnant with his child. Each interview reveals a new thread in a tangled web of relationships and possible motives.
The first round of questioning places Usha under emotional strain, her silence making the interrogation delicate. Chinnaiah Pillai’s account points to Pattabi as a potential killer and recalls a family feud over property: Pattabi had demanded his share, but Rajan refused, fearing squandered wealth. Pattabi, when confronted, expresses remorse for how he treated his brother and recalls tensions over the property dispute; he hints that Hema’s anger over the dispute could have driven a lethal act.
As Sivanandam turns to Hema, she starts with defiance but eventually cooperates, threatened with the prospect of arrest for her husband. She then reveals Rajan’s extramarital affair with Ambujam, a dancer who is pregnant with his child. Rajan’s cavalier response to the pregnancy troubles Hema, and she suggests Ambujam could be a killer driven by passion or desperation. Ambujam counters by accusing Chinnaiah, claiming Chinnaiah was her foster father and had urged her to distance herself from Rajan after a picnic meeting; the ongoing relationship between Rajan and Ambujam had inflamed Chinnaiah’s anger and created a motive for ending the liaison.
Sivanandam next questions Usha again, using a trick to collect fingerprints by urging her to use a leaky fountain pen. That evening, a gathering of suspects returns to Rajan’s house as Sivanandam conducts a controlled exercise: the suspects must pretend to be Rajan and shoot him with revolvers loaded with fake bullets. Pattabi and Hema shoot as instructed, but Usha breaks down and cannot pull the trigger. The exercise seems to tilt suspicion toward Pattabi and Hema until Usha finally reveals a buried truth.
The case takes a dramatic turn as Usha explains Rajan’s true life story: he was a radio engineer who hoped to bring affordable radios to the poor. His work earned attention in Japan, where he became entangled in espionage, selling India’s military secrets to Japan. Usha learned of his double life and tried, unsuccessfully, to reform him. Her attempts to stop him failed, and she had even attempted to shoot him herself; she changed her mind but pulled the trigger accidentally, killing him, and later cried at his boots, a stark image of remorse and tragedy.
The investigators press for the papers Rajan used to plan the bombings, and Usha goes to Rajan’s room to retrieve them. Sivanandam discloses that Usha’s fingerprints—those he collected from her and those on Rajan’s boots—correlate, amplifying the suspicion against her. When Usha takes a long time to return, a moment of silence is broken by a gunshot, and the team rushes into Rajan’s room, where Sivanandam calls out, “Usha!”
In the end, the film presents a layered portrait of a man who sought to leverage technology for social good while stepping into dangerous subterfuge, and a wife whose loyalty, fear, and love collided with the secrets of her husband’s life. The narrative unfolds against a backdrop of wartime politics, personal betrayals, and a chilling reminder that truth can be as complicated as the human emotions entwined with it.
