From a grim prologue set in the 12th century, Rangarajan Nambi [Kamal Haasan] a devout Vaishnavite, resists King Kulothunga II’s bid to desecrate a Vishnu idol, and is drowned along with the idol, a stark opening that threads faith, power, and sacred relics into the film’s core tension.
In 2004, Govindarajan Ramaswamy [Kamal Haasan], an Indian scientist working in the United States, is toiling on a dangerous project—a synthetic virus designed as a bio-weapon. When a lab monkey dies after ingesting the virus, Govind starts to grasp the magnitude of the threat he has helped create. He uncovers that his superior, Dr. Sethu, plans to sell the virus to terrorists, and in a tense escape he flees with the vial. In the scramble, the vial is accidentally shipped to India, triggering a desperate chase. An ex-CIA mercenary, Fletcher, is hired to retrieve it and leaves a bloody trail, cutting down Govind’s friends along the way. Govind’s pursuit leads him to Chidambaram, where the vial ends up in the possession of an elderly woman, Krishnaveni, who unknowingly hides it inside a Vishnu idol. Govind’s attempts to reclaim the vial are complicated by Fletcher’s relentless pursuit, local police, and Andal [Asin Thottumkal], Krishnaveni’s devout granddaughter, who views Govind as a thief rather than a savior and believes the idol must be protected.
The story broadens through a series of interwoven subplots: Fletcher’s translator-wife Jasmine [Mallika Sherawat] is killed during a tense clash involving a rogue elephant; Yukha’s brother Shingen, a skilled Japanese martial artist, arrives to avenge Yuka’s death; and RAW officer Balram Naidu keeps a watchful eye on Govind’s movements. Along the way, Govind and Andal cross paths with a spectrum of figures, including social activist Vincent Poovaraghan and a Muslim family headed by Kalifullah Mukhtaar, each adding texture to the escalating crisis. The vial is famously swapped with a medicine cooler belonging to Avatar Singh, a singer undergoing treatment for throat cancer, which further muddles the already tangled pursuit. As the stakes rise, Fletcher seizes hostages and demands the virus in exchange, dragging the tension through a dramatic sequence that culminates at Avatar’s concert, where the vial is ultimately returned to its original hiding place inside the idol.
With the danger intensifying, Govind discovers a potential way to neutralize the threat: immersing the virus in the ocean, because sodium chloride weakens it. A brutal confrontation erupts at a construction site between Govind and Fletcher, with Shingen stepping in to tilt the balance. Fletcher ultimately swallows the virus and dies as a colossal tsunami pounds the coast, erasing the immediate danger while leaving a path of devastation in its wake. Govind, Andal, and the remaining survivors endure the catastrophe, while Andal interprets the tsunami as a sign of divine intervention. Govind, however, remains a rational voice, questioning the morality of sacrificing vast lives as a solution to a single threat. In the end, the two souls find solace in each other as Govind is honored at a formal ceremony attended by world leaders, and the final image lingers on the idol’s remains washed ashore, a somber reminder of the long aftereffects of their ordeal.
