Zhao A'nuo, the second young miss of the Zhao family, is rumored throughout the city to be a simpleton. The Zheng family takes two brides at once: the talented elder sister is promised to the eldest young master who cannot get out of bed year-round, while A'nuo is matched with the newly imperial-ranked scholar. To keep her sister from spending a lifetime suffering by the side of a sickly man, A'nuo secretly switched the bridal sedan chairs on her wedding day, taking her sister's place to marry that sickly man instead. From then on, with a single needle she revives her wits, overturns accounts to clear grievances and battles the wicked mother-in-law, washes away her sister's wrongs, overturns the Zheng family's decade-long conspiracy, and unexpectedly wins the true heart of the sickly young master. She is not foolish, just too lazy to scheme—yet whoever bullies her sister, she thinks faster than anyone else.