Grandmaster

Chandrasekhar leads the new Metro Crime Stopper Cell in Kochi. He arrests Jerome, a psychologically deviant man, and rescues the three girls he had kidnapped. However, Deepthi, his ex-wife and a lawyer, intervenes and has Jerome sent to a psychiatric facility run by her friend Dr. Jacob rather than a prison sentence.

Chandrasekhar receives a congratulatory note from an anonymous figure calling himself Z. The note dares him to figure out how to bump off one target after another. This marks the start of a cat-and-mouse investigation into a series of murders.

A string of murders begins with Alice, a coffee shop owner, followed by Beena Thomson and Chandrika Narayanan. Each victim bears a cross slit on the forehead, and the killings appear to follow an alphabetical pattern. Chandrasekhar and his team realize a single mastermind is behind the crimes.

Meanwhile, Chandrasekhar's daughter Dakshayani is preparing for a school play led by the famous actor Mark Roshan. The case tightens as the family’s personal life intersects with the investigation.

Chandrasekhar reveals that he divorced Deepthi ten years earlier after discovering she used his information for professional gain. Deepthi admits that the three murdered women were involved in the murder of the rich NRI Paul Mathew, and that Chandrasekhar was the investigating officer at the time. This backstory connects the present case to the old one.

Chandrasekhar learns that Deepthi is the next target and accompanies her to their daughter's play. There they meet Victor Rosetti, a religious fanatic who has appeared at all three crime scenes, disguised as a salesman, and who has been secretly following Deepthi.

The recurring chess motif becomes a theme in the cat-and-mouse game between Chandrasekhar and Z. He decides to play a 'queen's gambit' in his own words, turning the investigation into a strategic duel. The mindset shift signals his plan to outmaneuver the mastermind.

Chandrasekhar corners Victor on the rooftop of a theater, and Victor commits suicide by falling to the pavement. The death marks a major turn in the investigation and eliminates one suspect.

Chandrasekhar questions Dr. Jacob and says he has evidence that he is behind the killings; Jacob is taken into custody. This shifts the focus away from Paul Mathew’s unresolved case.

Dakshayani disappears, prompting Deepthi to return to the school to search for her. A killer arrives and attempts to strangle Deepthi with a red scarf, escalating the threat.

Chandrasekhar corners the killer on the stage; the attacker is Mark Roshan Mathew, Paul Mathew’s younger brother. He reveals that he framed Dr. Jacob to mislead investigators and, with Rasheed’s help, moved Dakshayani to bring Deepthi to Mark.

Mark explains his elaborate plan, including disguising as Father Alexander to manipulate Victor and using theater scenery to stage the killings. He lunges at Deepthi with a dagger, but Chandrasekhar shoots him, ending the threat.

With the danger ended, Chandrasekhar, Deepthi, and Dakshayani are together again at their home. The case closes as the family finds stability after the harrowing events.