Nadiya Kollappetta Rathri

On the inaugural run of Sauparnika Express from Chennai to Mangaluru, Nadiya Mether is stabbed while two other victims, dancer Thulasimani and reporter Shreya Maria, are killed in the same compartment. The deaths create the impression of a connected crime, but investigators brace for a more complex mystery.

The case is assigned to DIG Sharafuddeen Taramasi of the Railway Anti-Criminal Task Force. Investigators question all passengers in the compartment and map possible connections among the victims, realizing the case may involve more than a single killer.

Muthuraj reveals an additional passenger, Lakkidi Manikandan, traveling in disguise as a police constable. Mani admits killing Shreya, motivated by her pursuit of Alexander IPS's smuggling operation. The motive links the murders to a network of crime rather than a lone killer.

Shreya's investigation into Alexander leads him to orchestrate Mani's murder as a cover. Near Salem, Shreya is forcibly removed from the train and killed, tying the case to broader criminal activity and smuggling.

Madhavan Master discovers that Nadiya is still alive and arranges transport to a hospital. The revelation shifts attention to how she survived and who else might be connected to the stabbing, complicating the timeline further.

In a subconscious memory, Balu recounts his meeting Priya the night of the killings and reveals a blade in his hand. Doctor Mathangi notices his presence and the blade found at the scene links him to the events. The memory helps anchor the sequence of events for investigators.

Investigation reveals Priya Rose and her mother Rajamma were smuggling gold on the journey. Rajamma's statements begin to expose their complicity, broadening the case beyond personal motives to organised crime.

Attender Sundareshan is identified as Thulasimani's killer, acting on orders from division manager Vijayabhanu. The motive centers on Thulasi's threat to reveal Vijayabhanu's advances and their secret marriage. The confession exposes a web of personal vendetta and professional corruption.

Sharafuddeen links the brutal Nadiya attacks to the twins' shared history, including Zakriya Mether, Janaki Iyer, and the distribution of Janaki's estate. Nadira inherits the artistic legacy while Nadiya becomes a star shooter, creating tension over wealth and belonging.

The team plans Narco-analysis tests to expose the twins' truth while Nadiya remains in a coma. Sharafuddeen reveals evidence that Nadira is the killer and points to the swapped identities, and the blood-group mismatch seals the real arrangement.

During the proceedings, it is revealed that Nadiya was the killer who stabbed Nadira and swapped identities to seize Janaki Iyer's estate. Overwhelmed by the truth, she leaps from the moving train and dies at a railway signal, while the real Nadira lies in a vegetative state.

Months later, Zia Musafir returns to take Nadira to the United States for advanced treatment, hoping she may recover. The academy and family grapple with the aftermath of the night’s events while the legacy and wealth are set on a slow path to healing.