Twenty:20
Retired Supreme Court Chief Justice Viswanathan Menon (Madhu) and his wife (Kaviyoor Ponnamma) come home to celebrate Vishu with his children (Siddique, Vijayaraghavan and Sindhu Menon) and grandchildren, and hopes to spend the remainder of his life in tranquility. The big joint family arrives and prepares to celebrate through the weekend, but plans go awry when Menon's grandson Arun Kumar (Indrajith Sukumaran), a medical student in Bangalore, is accused of murdering a fellow student.
The Superintendent of Police, Antony Punnekkadan (Suresh Gopi), who has a grudge against Menon's children, attempts to take Arun into custody. Arun goes into hiding, but Antony finds him and seizes him from the hideout. The Menon family hires ace criminal lawyer Ramesh Nambiar (Mammootty), who bails Arun out of jail. Vinod Bhaskar (Jayaram), a doctor and Professor of Medicine, wants to testify against Arun but is kidnapped by Karinkal Pappachan (Kalabhavan Mani), a thug hired by Menon's children.
Arun gets murdered and Superintendent Punnekkadan arrests Devan (Mohanlal), a poor trader who happened to be at the scene. Devan's sister (Kavya Madhavan) and his mother (Sukumari) tells Ramesh that Devan is innocent and that he is being framed by Punnekkadan. Ramesh takes the case, proves Devan's innocence in court, and Devan is released. Minutes after the release, Ramesh encounters Devan, who introduces himself as Devaraja Prathapa Varma, a crime boss. It is revealed that Devaraja and his assistants deceived Ramesh into believing that Devaraja was innocent. Devaraja reveals that he is the real killer and that he tricked Ramesh as retribution for saving Arun. Devaraja plans to avenge the brutal murders of his brother Karthik Varma (Dileep), who was killed by Arun and his cousins Mahindran (Manoj K. Jayan) and Ganeshan (Shammi Thilakan).
This triggers a feud between Devaraja and Ramesh. When Devaraja tries to kill the last two relatives involved in the crime, Ramesh sets a trap. Devaraja escapes but is eventually arrested by Superintendent Punnekkadan. Ramesh learns the truth about the murder at the Bangalore Medical College from Vinod Bhaskher (Jayaram), who is a teacher there and close friend of Devaraja's. Ramesh's sister Ashwathy is a student at the Bangalore medical college when she witnesses Arun killing a girl at the school. Arun, along with his two relatives Mahindran and Ganeshan, apprehend Ashwathy, inject her with morphine and Arun rapes her. Aswathy's boyfriend Karthik attempts to save her but he is killed and Aswathy falls into coma.
When Ramesh finds out Devaraja was actually trying to kill the criminals who defiled his sister, he is full of remorse. He remembers when Devaraja warned him that he would regret knowing the truth. Devaraja escapes from police custody with the help of a police officer (Sreenivasan) and he kills Ganeshan. Then Ramesh kills Mahindran and Superintendent Antony kills Arun's father Madhavan (Siddique). The case is abandoned when the Superintendent lets them walk free, knowing that otherwise they would escape anyway.
revenge, murder, flashback