Poor girl Dou Er sells herself in order to afford a proper burial for her mother. Dou is bought by a woman,Cai, who weds her son Changzong to the girl. They become a loving couple. After a time, Changzongtravels to the capital to take the imperial examination but sends no word back to his family. Informed of the situation, Zhang, who has long coveted Dou for her beauty, hires a man to kill Changzong. The attempt fails, but word travels back to Dou and Cai that Changzong is dead.
With Changzong presumed dead, the women have to fend for themselves. Zhang starts paying frequent visits with advances and marriage proposals, but all meet with defiance. Zhang then tries to kill Cai, the mother-in-law, by giving her poisoned soup, but his own mother eats the tainted food by mistake and dies.Zhang accuses Cai of murdering his mother and bribes the magistrate into extorting a confession through torture. Fearing that her mother-in-law will not be able to withstand the prosecution, Dou takes responsibility for the crime instead.
On the day of her execution, in the middle of summer, an amazingly heavy snow descends. Changzong, fresh from winning first place in the imperial examination, returns as inspector general. Noticing the unseasonable snow as an omen of extraordinary injustice, Changzong personally retries the case and exonerates Dou while bringing Zhang to justice. The family is happily reunited.