Madhavan (Elango Nagarajah), a young man, lives with his joint family : parents (Manobala and Fathima Babu), brother (Sriman) and sister-in-law (Yuvarani). His family has a feud with their opposite house family (M. S. Bhaskar, Subbu Panchu Arunachalam, Meera Krishnan and Devadarshini). Pambukutty’s daughter Deepika (Anjana Keerthi) was into a boarding school in Ooty for 10 years, where she completes her education and comes back to her native. Deepika’s family decide to get her married off while Keeripulla also wants his son to get married. Soon, Madhavan and Deepika fall in love with each other. What transpires next forms the rest of the story.

A young mechanic falls in love with a rich girl; her father plots to break their relationship, as a result, the mechanic murders a manager while trying to save the girl’s honor.

An undercover officer who handles the missing case is unfolding the mystery behind the crime

A normal man from a middle-class family questioning the authorities for abusing their powers.

Vijay Kumar (Vijay) is an honest and sincere DCP of Chennai. He takes up a case involving the rape and subsequent death of an IT employee Raji. He finds out that the rapist is Ashwin, the son of Labour Minister Vanamaamalai (J. Mahendran). Vijay kills Ashwin and reveals himself as the murderer to Vanamaamalai, who swears to take revenge on him for killing his son. Meanwhile, Vijay falls in love with a medical student Mithra (Samantha Ruth Prabhu) and both eventually get married and lead a happy life. But, Vijay’s happiness is short-lived as Vanamaamalai, his younger brother Ratnam (Azhagam Perumal) and their henchmen barge into his house one night and kill Mithra and Vijay’s mother (Raadhika). They even brutally assault Vijay and attempt to drown Vijay’s baby daughter Niveditha aka Nivi in the bathtub. The dying Mithra manages to rescue Nivi and asks Vijay to take care of her, but not before making him promise that he will quit the police and be a peaceful and loving father to Nivi, following which she dies in Vijay’s arms. Vijay fakes his death, changes his name to Joseph Kuruvilla, maintains a low profile and moves to Kerala with Nivi and his constable friend Rajendran (Rajendran) to protect Nivi from Vanamaamalai and his gang.

Inspector Ajit Rathod (Ajay Devgn) is on a mission to eliminate a notorious terrorist Azhar Khan (Rahul Dev) who killed his wife (Koena Mitra) and the latter is underground from the eyes of law and planning to destroy Mumbai. Now the story moves on to Amjad (Akshay Kumar), an auto rickshaw driver, who is searching his long lost brother Munna, and struggler Avinash (Tusshar Kapoor) who wants to be a star in Bollywood industry. Amjad wants to marry his lover Heena (Esha Deol). But her parents want her to marry a rich man. So Amjad plans to win her parents’ trust by a fake drama with Avinash and his friend to act as fake goons and they involve Rathod to arrest and win Heena’s heart. The plan goes wrong as real goons appear but Amjad fights them leading t Heena’s parents agreeing to marry her to Amjad. Avinash, who is a struggler, on the other hand, loses his job as an extra in films after an argument with an egoistic actor. A newcomer Indu (Laila Mehdin) is helped by Avinash to enter the industry and soon both fall in love with each other not knowing that she had been subjected to a compromise with the producer. Hopeless, Avinash decides to be an auto-rickshaw driver but Indu apologises and encourages Avinash to be a good actor. Soon, Avinash and Indu’s luck turns when the filmmaker (Asrani) casts them as leads in his next film after being impressed on their acting skills. Meghna, a news reporter (Lara Dutta) develops a liking towards Rathod, but the latter is still traumatised and angered on his wife’s death.

An inebriated filmmaker finds himself in a shocking situation when he realises that the mysterious girl who accompanied him to her room has been killed.

Later, Arivu joins a leading FMCG company Saffron and joins its sales department under Stella Bruce (Thambi Ramaiah). He also manages to bring his friend Bhagya (Vijay Vasanth) out of Kasi’s gang and gets him a job in Saffron. He meets Aadhi (Fahadh Faasil), Saffron’s brand manager, who teaches him how to progress. On the night of April 1, Kasi and his gang stab Bhagya. Arivu tries to attack Kasi, but Kasi’s rival Doss (Sharath Lohitashwa) stabs Kasi, and Arivu admonishes Kasi for being a paid henchman. Kasi reveals to Arivu that he killed Bhagya on a contract given by Jayaram (Anish Kuruvilla), the President of Saffron, due to the fact that Bhagya tries to help Kasthuri (Sneha), who files a case claiming Saffron’s products to be adulterated, due to which she had lost her son. Arivu is addressed by Kasi as being a worse hitman than he himself is. Arivu then saves Kasi. Kasi tells Arivu that all the products manufactured by this company are adulterated. Arivu takes up a mission to fight such malpractices not only in Saffron, but also in all the other five major food companies, including the company owned by Madhav Kurup (Mahesh Manjrekar). Arivu shares all of his plans with Aadhi. It is revealed that Aadhi is Adhiban Madhav, Madhav’s son. He joined Saffron to know their trade secrets and merge the company with his father’s company.

Pandian vows to catch a drug kingpin after his partner is murdered. When he is kidnapped and turned into an addict, Pandian fights to overcome the addiction and get revenge for his friend.

Thenmozhi (Anushka Shetty) arrives in Boston to meet her niece. While leaving for Chennai, in the airport, she gets a free upgrade and sits next to Sathyadev (Ajith Kumar). During the flight, she starts vomiting due to overeating and with Sathyadev’s help she feels better, so she develops a crush on him. The next day in Chennai, Sathyadev and Thenmozhi are at a cafe, when a criminal named Victor (Arun Vijay) comes to abduct Thenmozhi, but fails due to Sathyadev subduing him.

The film goes back to Chennai 1989 (then known as Madras) where Sathyadev’s father (Nassar) is killed by a criminal. From there, Sathyadev makes a decision and a few years later is seen in a jail with Victor. They escape from jail, get Victor married to Elizabeth alias Lisa (Parvathy Nair), and meet a criminal Matthew (Stunt Silva). Sathyadev infiltrates the gang as an IPS officer, kills Matthew, and injures Victor. In an attempt to stop a gangster, he meets Hemanika (Trisha Krishnan), who needs to get to a hospital due to her being pregnant. Two years later, he meets Hemanika and her child Isha (Baby Anikha). After seeing each other for four years, they decide to get married. On the day of their marriage, Hemanika is killed: Sathyadev and Isha are heartbroken. Sathyadev decides to quit and travels with Isha around India along with his colleague Richard’s (Vivek) help. After he returns, his neighbour’s children have gone missing. He discovers that Victor is helping his boss Muruganandham (Suman), stealing organs illegally with foreign doctors to help him. Sathyadev is able to find the children and their next target, Thenmozhi.

Vallarasu (Vijayakanth) is the Deputy Commissioner of Police and a very honest police officer who has arrested Wasim Khan (Mukesh Rishi), a terrorist from Pakistan. He has a wife Anjali (Devayani) and 2 children. Vallarasu kills his senior police officer (Raghuvaran), who is his father-in-law, on knowing he is hand-in-glove with terrorists and anti-national elements. Anjali leaves Vallarasu after she comes to know he had killed her father. Vallarasu takes the help of some youths (including Sriman) who are disillusioned by their inability to join the police force to fight the terrorists and other criminal elements. Vallarasu fights R. Kandasamy (P. Vasu), a rich man who is behind the attempts to destabilize the country. With the help of Seshadri (Karan), a software engineer, Vallarasu succeeds in killing Kandasamy’s son. In retaliation, Kandaswamy attacks Raheem (Sriman) and Seshadri, who both die. In the climax, Anjali unites with Vallarasu after knowing the truth, and he kills both Kandasamy and Wasim Khan.

The epic next chapter in the cinematic Monsterverse pits two of the greatest icons in motion picture history against one another – the fearsome Godzilla and the mighty Kong – with humanity caught in the balance.