Superstar Mohanlal takes up the role of a divorcee in the film, Grandmaster. He lives alone in a dark and violent city. Even when unlawful incidents take place around him, he withdraws himself from all responsibilities and is happy to live quietly. But he is forced to change and take up his duties and responsibilities. Like a grandmaster who anticipates his opponents moves well in advance, he proceeds forward. But only once, just once, he makes a fatal mistake and his whole life is drastically altered.