"Thoongaa Vanam" (2015) is a Tamil action thriller film directed by Rajesh M. Selva and written by Kamal Haasan. It features Kamal Haasan, Prakash Raj, and Trisha Krishnan. A policeman's covert operation becomes a thrilling night of survival after a drug lord kidnaps his son in return for a stolen bag of cocaine.
C.K. Diwakar (Kamal Haasan), an IRS officer with the Narcotics Control Bureau, steals a shipment of drugs secretly along with his friend Mani but gets hurt in doing so. Crime lord Vittal Rao (Prakash Raj) kidnaps Diwakar's son Vasu in revenge and demands the stolen drugs back. Diwakar is made to carry the cocaine to Vittal's nightclub but stashes it in a toilet. Meanwhile, NCB officer Mallika (Trisha Krishnan) observes his suspicious behaviour and informs her boss, Dhiraviyam. Dhiraviyam steals the bag unsuspected by Diwakar. In desperation, Diwakar attempts to deceive Vittal with a bag of milk powder, only to get caught in his own deception. In the struggle with Vittal's gang and coping with his deteriorating injury, Diwakar informs Mallika that he is really an undercover operative who has come to catch crooked cops.
As the chase intensifies, Diwakar secretly rescues Vasu. Mallika, now suspicious of her own team, finds proof on Mani’s phone of Diwakar’s undercover work. Vittal gets arrested, and the role of Dhiraviyam comes to light. Diwakar falls from a loss of blood but survives after he is admitted to the hospital by his son. Three months later, Diwakar has regained strength, and Mallika is now working as his trusted ally in the force.
"Thoongaa Vanam" is a gripping and tightly made thriller that takes place in one night. Kamal Haasan excels as the committed cop torn between duty and paternity. The movie is paced tightly, with slick action and rich emotional content. A combination of suspense, betrayal, and redemption, it is a gripping watch that keeps the viewers hooked till the end.