IG Chandrasekhar, Mohanlal, heads the newly formed Metro Crime Stopper Cell in Kochi. He arrests Jerome, a psychologically deviant man, and rescues three girls he had kidnapped, but his ex-wife Deepthi, Priyamani, a lawyer, intervenes and secures Jerome’s placement in a psychiatric facility run by her friend Dr. Jacob, rather than a prison sentence. It later becomes clear that the three girls had been taunting and harassing Jerome, which contributed to his actions. The case sets off a chilling game of cat-and-mouse, where motive and misdirection blur the line between victim and perpetrator.
Chandrasekhar receives a taunting note from an anonymous figure who signs off as "Z," challenging him to anticipate how a single target will be eliminated after another. This mysterious antagonist pulls him into a brutal string of murders: Alice, a coffee shop owner; Beena Thomson, a famous singer; and Chandrika Narayanan, a leading businesswoman. Each victim bears a cross slit on the forehead, and the killings unfold with an eerie, almost scripted, alphabetical pattern. First comes Alice, then Beena Thomson, followed by Chandrika Narayanan, each death tightening the noose around the detective as the city scrambles to understand the pattern. Throughout these investigations, Chandrasekhar’s focus remains unwavering even as personal life intrudes; his school-going daughter Dakshayani is meanwhile preparing for a play under the lead of the renowned actor Mark Roshan. The juxtaposition of a family moment and a deadly pursuit heightens the stakes.
Deepthi and Chandrasekhar’s backstory adds a layer of tension: they divorced ten years earlier when he discovered Deepthi had been using information from him for professional gain. In a revealing confession, Deepthi tells him that the three murdered women were involved in the murder-for-suicide of a wealthy NRI named Paul Mathew, and that Chandrasekhar, in his earlier role as SP, had been the investigating officer on that case. This revelation reframes the present killings as connections to past events, and Chandrasekhar suspects that Deepthi herself may be targeted next. Siddique appears in the backstory as the link to Paul Mathew’s case, anchoring the loop between past and present crimes.
Seeking protection for Deepthi, Chandrasekhar accompanies her to their daughter’s play, where they encounter a religious fanatic named Victor Rosetti who had already appeared at the crime scenes, disguised as a salesman and shadowing Deepthi. The pursuit takes on a chess-like texture, with Chandrasekhar noting the recurring recurrence of the game between him and the mysterious Z. The detective recognizes that a mastermind is orchestrating the violence and decides to counter with a strategic, calculated move—a “queen’s gambit” of his own, as he puts it. The tension of warring intellects is palpable, and the audience is kept guessing about who truly controls the board.
The hunt leads to a rooftop confrontation where Chandrasekhar corners Victor, and the would-be mastermind takes his own life by leaping to the pavement below. With Victor out of the picture, Chandrasekhar interrogates Dr. Jacob and believes he has a solid case against him, taking the doctor into custody. Anoop Menon’s portrayal of Jacob anchors a crucial turn in the investigation, as the physician’s role becomes central to unraveling the truth behind the murders.
Dakshayani’s disappearance after these events compounds the peril, and Deepthi returns to the school to search for her daughter. A real serial killer then emerges and attempts to strangle Deepthi with a red scarf, heightening the danger and forcing Chandrasekhar to close the net once more. He finally corners the killer on stage, where a dramatic reveal shifts the entire course of the case. The culprit is Mark Roshan, played by Arjun Nandhakumar in a chilling twist; the young actor is revealed as Paul Mathew’s younger brother Roshan Mathew, who had manipulated Victor and misled Chandrasekhar’s investigation. Mark admits to orchestrating the murders and to framing Dr. Jacob to misdirect the investigation, while relocating Dakshayani with the help of his associate Rasheed to draw Deepthi away from the theater.
Mark’s motive—holding a grudge against the women tied to his brother’s death—unfolds in a confession, and the killer even admits to having used a disguised persona, Father Alexander, to mold Victor into believing he was the killer. He hoped to execute the final murder of Deepthi during the play, using the stage’s scenery as a weapon. In a climactic struggle, Chandrasekhar fires, killing Mark and saving Deepthi from a fatal blow. The truth in these moments reveals Mark’s calculated manipulations and the long shadow of Paul Mathew’s death over a web of past and present crimes.
The film ends on a note of family reunion and renewed solidarity: Chandrasekhar, Deepthi, and Dakshayani are finally together again in their home, where the broken threads of the past begin to mend in the warmth of a united family. The narrative, anchored by a relentless pursuit of truth and a chess-inspired battleground of wits, leaves the audience with a sense of closure even as it lingers on the moral complexities of justice, vengeance, and forgiveness.
