'Second Show' is a dark crime thriller that begins with the flashback of an ex-convict Hari (Dulquer Salmaan) as narrated to a man he meets at a bus stop on a rainy night. It is revealed that Hari (whose nickname is Lalu) is a poor young man who works for the local sand mafia as a driver. He is friends with Kurudi (Sunny Wayne) whose real name is Nelson Mandela PP.
One day while at work, Kurudi draws Lalu to a fight leaving the sand smugglers without a driver that causes them to get caught by the police. Now jobless, Lalu and Kurudi join the group of Chaver Vavachan (Baburaj), who is a financier, and take up the job of retrieving vehicles for non-repayment of loans.
Chaver Vavachan is the younger brother of a notorious former goon 'Chaver Antony' who dies due to a cracker burst by a young lad. Vavachan swears revenge and, after a long wait, finds the lad (who is now a man) at a hospital and bursts crackers on him. The injured however happens to be one of the henchmen of an influential smuggler, Vishnubuddhan(Sudesh Berry) who, enraged, kills Vavachan. Impressed by his courage, Vishnubuddhan takes Lalu into his gang. During one of Vishnubuddhan's deals, Lalu is betrayed by one of his friends and Vishnubuddhan mistakes Lalu for making away with the goods.
Vishnubuddhan's henchmen severely thrash Lalu, forcing him to flee. He however returns as a smuggler in his own right and starts overshadowing Vishnubuddhan. Angered by this, Vishnubuddhan kills Kurudi and Lalu avenges his friend's death by killing Vishnubuddhan and taking over his business. However, Lalu is eventually caught by the police and sent to prison.
Back in the present, as Lalu finishes his narration, he sees Vishnubuddhan's son sitting in a car parked nearby. Realising it to be a trap, Lalu becomes alert but the man to whom Lalu has just narrated his story shoots him. Before leaving the man reveals that he was actually sent by Vishnubuddhan's son to kill Lalu. The final scene shows Lalu lying badly wounded but his hand moves slightly, revealing that his chapter is not yet over.