Dum is an action thriller drama that revolves around Uday (Vivek Oberoi), who comes from a middle-class family and aspires to be a police officer. Despite the lack of recommendations, Uday believes that he’ll make it big by his abilities. He works hard to realise his dream. However, a senior police inspector, Shankar (Atul Kulkarni) is an egoistic and corrupt cop, who uses his powers for everything wrong. One day, Uday’s girlfriend Kaveri (Dia Mirza) gets into an argument with Shankar, who then tries to slap her, but Uday intervenes and indulges in a fight with him. Shankar makes Uday’s life difficult since then. Will Uday be able to stand against this powerful cop and expose him?