Grandmaster

These three women were targeted because they were directly involved in the murder-for-suicide of a wealthy NRI named Paul Mathew years earlier. Chandrasekhar had investigated that case when he was SP, and the women were revealed to be complicit in Paul's death, which became the motive for the present killings.

The alphabetical sequence of victims mirrors the calculated, theatrical approach that would later be revealed as Mark's signature.

Z is the anonymous figure who taunts Chandrasekhar with notes challenging him to anticipate how targets will be eliminated. The identity is never directly revealed through these messages, as Z operates through cryptic notes while orchestrating the murders from behind the scenes.

The taunting notes establish the chess-like cat-and-mouse dynamic that defines the investigation.

Mark Roshan is actually Roshan Mathew, the younger brother of Paul Mathew. He orchestrated the murders of Alice, Beena Thomson, and Chandrika Narayanan as revenge for their role in his brother's death years earlier. The killings were part of his elaborate plan to avenge Paul Mathew.

Mark's involvement as a beloved actor directing the school play creates a deceptive cover for his true identity and motives.

Victor Rosetti was a religious fanatic who was manipulated by Mark Roshan. Mark disguised himself as Father Alexander to mold Victor into believing he was the actual killer, using him as a pawn to carry out the killings while misdirecting the investigation. Victor appeared at crime scenes disguised as a salesman and followed Deepthi.

Victor's presence at all crime scenes and his fixation on Deepthi suggest a deeper manipulation at play.

Deepthi was targeted because she was involved in securing Jerome's placement in Dr. Jacob's psychiatric facility, making her connected to the present investigation. Additionally, as the lawyer who had previously helped in the Paul Mathew case cover-up, she was the next logical target in the revenge plot. Mark planned to kill her during his staged play performance.

Chandrasekhar's realization that Deepthi may be targeted sets up the protective measures at the school play.

Mark framed Dr. Jacob by using Victor Rosetti as a puppet to make the killings appear connected to the psychiatric facility. By manipulating Victor through his Father Alexander persona, Mark created evidence pointing to Dr. Jacob, leading Chandrasekhar to temporarily arrest him as the prime suspect.

The false evidence against Jacob misdirects the investigation and delays the discovery of the true mastermind.

When Chandrasekhar cornered Victor on the theater rooftop, Victor realized his plan had been exposed and his identity as a pawn was uncovered. Rather than be captured, Victor chose to end his own life by jumping to the pavement below.

Victor's fanaticism and belief in his mission made suicide a likely outcome when confronted.

Chandrasekhar's 'queen's gambit' refers to his decision to turn the investigation into a strategic counter-offensive against the mastermind. Recognizing the chess-like cat-and-mouse game, he shifted from reactive investigation to proactive maneuvering, using the antagonist's own patterns against them.

The chess motif runs throughout the film, with Z challenging Chandrasekhar to anticipate moves.

Mark kidnapped Chandrasekhar's daughter Dakshayani to draw Deepthi away from the theater and the protective presence of Chandrasekhar. With Deepthi isolated, Mark could attempt to kill her during the play without interference, using the stage scenery as a weapon.

Dakshayani's disappearance triggers Deepthi to leave the safety of the theater, playing into Mark's plan.

Mark was revealed as the mastermind when Chandrasekhar cornered him on the theater stage during the confrontation. The killer was identified as Mark Roshan Mathew, Paul Mathew's younger brother, and he confessed to orchestrating the murders, framing Dr. Jacob, and manipulating Victor Rosetti.

Mark's position as the beloved actor directing the play provided him both access and cover for his elaborate scheme.