Sona Mukerjee tells her husband Mrityunjoy “Joy” Mukerjee that she's pregnant. Inspector Imran Shahid, who is also Sona's ex-boyfriend, visits her house to collect evidence against Joy in a serial killing case. Sona believes Imran is framing Joy to take revenge on him for taking away his love.
The serial killing case centers on six missing girls whose bodies are later found in an isolated house owned by Joy. Joy, a respected gynecologist, is arrested, and the town’s people begin to lose faith in him. Sona, convinced of Joy’s innocence, visits him in prison, and Joy urges her to seek help from a famous lawyer, Brij Rastogi, whom he had saved before. Joy’s bail application is rejected because the evidence seems stacked against him, and Rastogi counsels a controversial tactic: if Sona could trigger another death in the same pattern, it would prove the killer isn’t Joy.
Sona is a kind-hearted person who dislikes hurting others, but she agrees to Rastogi’s plan after weighing every option. She selects her neighbor Anushka Tiwari, an unmarried pregnant woman, as the next “case.” News of Anushka’s death reaches the police, and the court begins to believe Joy isn’t the killer, allowing him to post bail. After Joy returns home, Sona reveals Anushka is still held captive by her, and, in a shocking twist, Anushka’s apparent death was staged: Sona had found an unclaimed body and dressed it to resemble Anushka’s.
Meanwhile, Anushka’s boyfriend Sid follows the pair and discovers that Anushka is actually alive, hidden in the basement of Joy’s clinic. Sid tries to free her but accidentally locks himself in a cupboard. Sona wakes in the night to find Joy missing; she races to the clinic and finds Joy approaching Anushka with a deadly plan. The mounting tension makes her realize that Joy is indeed the killer she’s trying to combat. Joy reveals his motive: his mother’s pregnancy out of wedlock and abandonment shaped his hatred of pregnant girls, driving him to abort and dismember them.
Sona makes a desperate bid to save Anushka, but Joy pins her hand to a table with a scalpel. Sid is tied up by Joy, yet manages to contact Imran, who arrives but is also captured. Imran eventually breaks free and frees Sona; together, they help Sid and Anushka escape. In the chaos, Joy stabs Sona as she lunges to shield Sid and Anushka, and Imran delivers a fatal stab from behind, presumably ending Joy’s life.
Sona wakes in hospital beside Imran and learns that she has lost her baby. Imran explains that Anushka is not pressing charges against Sona because she owes her life for saving her. Joy survives the doctor’s intervention and evades hospital surveillance, while Rastogi’s deeper knowledge of Joy’s crimes comes to light; he has, at times, shielded Joy. The tangled web leaves Joy facing an uncertain future, with the truth about his crimes and their consequences lingering long after the ordeal.
