The film begins with Petta, a retired don, leading a peaceful life as a school principal. He runs the school with an iron fist but with a heart of gold. However, things take a turn when a new student, Kumar (played by Vijay Sethupathi's lookalike), a soft-spoken yet lethal killer, joins the school.
Kumar had had a troubled past and becomes a student in the school under a pseudonym. Petta tries to understand Kumar and reform him, but their bond transforms into a thrilling cat-and-mouse game when the school becomes a battleground. The film begins with Petta, a retired don,
The climax portrays Petta's understanding of Kumar's character and motive, leading to a final confrontation with the real enemy. The film begins with Petta