Ek Hasina Thi

Sarika, a single woman in Mumbai, meets Karan and initially resists his advances. Over time they fall into a relationship, sharing moments of affection and companionship. The budding romance introduces Karan as charming but enigmatic.

Karan asks Sarika to host his friend who is new to the city, and she agrees to help him. The friend leaves behind a suitcase at her home, asking to pick it up later before his flight. That evening, news reveals the man is a wanted criminal, shocking Sarika and setting off alarm bells.

Sarika steps out with the suitcase to clear it from the home, but police intercept her and arrest her. Karan instructs her to speak to his lawyer, Kamlesh Mathur, and to never mention his name in the investigation to protect his reputation. The arrest entangles her in a case she did not anticipate.

Karan’s lawyer Kamlesh Mathur convinces Sarika to confess, arguing that the judge will show leniency given her clean record. Trusting the attorney, Sarika admits to the crime, thinking it will lead to a light sentence. Instead, the judge sentences her to seven years in prison without parole, and she soon realises she has been manipulated.

The news of her father's death reaches Sarika while she remains imprisoned, deepening her despair. She realises the consequences of Karan’s deception and the personal cost of her imprisonment. A growing hatred toward Karan begins to take root as she endures the harsh prison environment.

Inside the prison, Sarika begins a journey of self-transformation. She confronts her fear of rats, an obstacle she once believed would define her fate. In a display of newfound courage, she also stands up to Gomati, a fellow inmate who had bullied her.

Sarika orchestrates an escape with a small group of inmates after starting a fire in the prison kitchen. The ruse works, and they slip away from captivity as authorities scramble to contain the blaze. In the chaos, she becomes a fugitive.

After her escape, Sarika tracks down Kamlesh Mathur and kills him, realizing he was complicit with Karan in the plan. She learns that Karan is operating from Delhi for a gangster network, sharpening her resolve to confront him. The act marks a decisive turn from prisoner to pursuer.

Sarika travels to Delhi to find Karan and sets up shop opposite his room, observing him day and night without arousing suspicion. ACP Malti Vaidya picks up her trail and starts to connect the dots between the missing Karan and Sarika. The cat-and-mouse game intensifies as she stays one step ahead of the law.

Karan is abducted from a nightclub by Sanjeev's henchmen, and Bilal alerts him that Sanjeev is ready to meet. After a tense encounter, Sanjeev is found dead, casting suspicion on Karan. The criminal web around him tightens as the police close in.

Karan and his girlfriend are attacked in a hotel, and several henchmen perish in the chaos. ACP Malti arrives in time to confront Sarika’s possible involvement, while Karan panics over the turn of events. The momentum shifts as multiple players duel for control of the situation.

In a final showdown, ACP Malti kills Karan's boss, and the ACP herself is wounded in the exchange. Karan briefly escapes, but Sarika corners him, drives him to a secluded cavern, and locks him inside. She reveals her motive and ultimately leaves him to die as rats crawl over him.

Sarika turns herself in to ACP Malti, handing over the bag of money she had stolen from Karan's boss. The case closes as she surrenders her vengeance and accepts the consequences of her actions. The film ends with Sarika's uneasy sense of justice and closure.