Thupparivaalan

Dhivakar, an IT company owner, celebrates his birthday with his family. A sudden bolt of artificial lightning rips through the celebration, burning him and his son to death. The tragedy triggers investigations that drive the rest of the story.

In a cinema, a man gropes a woman, triggering a brief commotion that is quickly contained. The incident hints at the darkness lurking beneath ordinary life and foreshadows the crime network in the plot.

Three days after the cinema incident, ACP Paul Dhanarajan dies in the middle of a police conference after intervening. His death shocks the force and sharpens the investigation into the hidden conspiracy.

Detective Kaniyan Poongundran (Kani) and his associate Mano are introduced as a team. They cross paths with Mallika after a pickpocketing incident, and she later becomes the housekeeper at Kani's home.

Naveen, a schoolboy, asks Kani and Mano to find his missing dog Nemo after a bullet is recovered at the scene. The bullet is identified as 9mm and shows a ricochet, and a tooth traced to Swarnavel connects the case to a hidden past.

Kamalesh visits a travel agency to deliver a stash of money to five individuals who operate as assassins: Devil, Muthu, Pritha, a stout man, and a bald man. The arrangement signals a larger conspiracy behind the Dhivakar tragedy.

Kani recalls a news article about Dhivakar's death and learns Swarnavel was present at a nearby construction site on the day. He concludes that Swarnavel engineered the artificial lightning that killed Dhivakar.

At Dhivakar's office, Kani and Mano learn the tender to be awarded to Dhivakar is now in Ram Prasad's hands. Before they can reach him, Ram Prasad is assassinated, escalating the chase.

Kamalesh hires Chinese mercenaries to kill Kani. Kani defeats them, and in a twist of fate, Pritha kills Kamalesh to cover their tracks.

A day later in a shopping mall, Pritha makes a failed attempt to kill Kani, but Mallika intervenes and saves him. The close call heightens the danger surrounding them.

Kani and Mano meet Police Inspector Madhivanan and ACP Vijayakumar at a hotel, where another assassination attempt occurs. Muthu plans to inject Kani with a poison dart, and Mano is caught in the crossfire and rushed to hospital.

The team raids the travel agency; Devil kills Muthu to cover his tracks, and they discover physics books related to lightning that link back to Swarnavel's scheme.

During interrogation, Madhivanan reveals that Ram Prasad hired Devil and his team to kill Dhivakar to secure the tender. Swarnavel feels guilty and tries to expose their involvement, but Devil and his crew murder him; Nemo bites Devil, and Swarnavel's body is hidden in the office fridge.

Kani, Mano, and Vijayakumar pursue Devil to a mangrove forest. A brutal firefight erupts and all but the three of them die, tightening the noose around the mastermind.

Devil captures Kani and Vijayakumar and uses Naveen to threaten them. Kani explains how he uncovered Devil's backstory, then kills Devil. In his dying moment, Devil apologizes to Naveen for Nemo, and Naveen finds a Pomerarian puppy with a note from Kani on his doorstep.