A gripping tale of crime and redemption unfolds through a series of nine murders that terrify a small community. Derick Abraham, an ASP, begins piecing together clues to uncover the identity of the serial killer. Using the killer's note, he deduces that the perpetrator is a fanatic Christian extremist targeting atheists, revealing a disturbing motive behind the gruesome acts. The investigation leads him directly to Brother Simon, a member of the local seminary, whom Derick captures. Simon confesses he is aiming to reach a count of ten victims. However, when Derick returns to question him again, Simon is found dead, with a slash on his throat and a knife in his hand — leading Derick to believe that Simon took his own life, thus becoming the tenth victim himself. This tragic incident results in Derick being suspended from duty, although he eventually manages to get reinstated.
Derick's personal life is marked by tragedy and strained familial ties. His family consists solely of his younger brother, Philip Abraham, who is training as a sharpshooter. Their parents died early in a car accident, leaving a void in their lives. The story intensifies as Philip is falsely accused of murdering his girlfriend, Aleena Maria Jacob, and is severely beaten by Narayana Sethupathi, a senior police officer. Despite protesting his innocence, Philip is arrested, and Derick is compelled to carry out his brother's detention. Overcome with grief and frustration, Derick turns to alcohol, gradually losing his grip on reality.
The situation escalates further when Philip, furious and feeling betrayed, resents Derick and vows revenge after being imprisoned. With the help of Dinesh Slug, a corrupt jail warden, Philip escapes custody, fueled by hatred and a desire for retribution. Dinesh and Narayana hold a grudge against Derick from past criminal cases involving their sons, which fuels their complicity in Philip's daring escape. During his time outside, Philip is accompanied by his close friend Nisam, who later reveals troubling facts about the night of Aleena’s death. According to Nisam, Philip was heavily intoxicated and sleeping while others—Arun and Salman—accidentally killed Aleena when she came to meet Philip at the beach, and he had no involvement.
As suspicion and chaos grow, Derick becomes desperate to prove Philip's innocence. Meanwhile, Nisam’s subsequent suicide raises questions about the case's true nature. Philip’s paranoia and hatred deepen, leading him to attempt to kill Derick in a supermarket—an act that fails. The police, led by Shahul Muhammed IPS, pursue the truth and eventually find Arun and Salman at a car wash, who refuse to surrender. In a heartbreaking twist, it is revealed that Arun and Salman are not innocent—they were hired to kill Aleena and were paid, with the money arranged into a ₹ ten crore ransom, to stay silent and avoid detection.
Dinesh, alongside Sukumaran and the other officers, uncover that the real mastermind was Derick himself. It turns out that Derick orchestrated everything: he planned Philip’s escape to ensure his safety, framed the actual culprits, and killed Arun and Salman himself to eliminate witnesses. The entire scheme was meticulously enacted to protect Philip and send him abroad to start anew, with the ransom money used as part of the escape plan.
In a poignant farewell scene, Derick bids an emotional goodbye to Philip, acknowledging his own sacrifices. The story concludes with a twist: at the police station, Johnny mocks Derick’s suspension from three years earlier, but it's ultimately revealed that Derick was responsible for the death of Brother Simon, having discarded evidence that might have implicated him. His complex morality leaves a lasting impact as he walks away, burdened by the truths behind the crime and his own actions, leaving viewers to ponder the thin line between justice and morality.
