Kaun?

On a stormy rainy night a women is watching a news on television of a killer being around suddenly her bell rings.She is hesitant to open the door after hearing the news of killer.Man claims himself as Sameer A. Purnavale looking for Mr Malhotra and frequently rings the bell.The women tells him that the house belongs to Mr Gupta.In order to scare him she tells that her husband is sleeping upstairs.But she hears a sudden noise and runs outside to Puranavale who tells her that he is here to protect her.When she finds nobody around asks him to leave but another man is standing at the door with a gun claiming to be Inspector Qureshi.The women is left confused among both the men suspecting that they are not who they claim to be as one of them could also be the killer.