Mala (Rani Mukerji) works as a computer science engineer. One day her friend confides in her about her love affair with the son of a wealthy man, who has been intimate with her, but now is marrying someone else. Mala accompanies her friend to this male's wedding, disrupts it, and eventually ends up ruining the event. The groom's brother, Raja (Shadaab Khan), is enraged and insults Mala, in response to which she slaps him. Enraged all the more, Raja seeks Mala out, and in the presence of her pupils, brutally slaps and then rapes her. The police get involved and Raja is arrested.
Raja's dad, Rai Bahadur Diwanchand, attempts to give some money to Mala's guardian, Gyani Kartar Singh, who refuses to accept it. The court case proceeds, and the Judge, overcome by Mala's evidence, finds Raja guilty, convicts him, and orders that he marry Mala within the next twenty-four hours. Raja's attempts to kill Mala are in vain, and both get married with great pomp and ceremony. After the marriage, Rai Bahadur goes overseas, and leaves his family, especially his elder daughter-in-law, Sharda, to deal with Mala, and ensure that she is belittled, beaten, and eventually driven out of their house. Will Mala be able to face up to the dominating Sharda and the rest of this family, in addition to Raja?