太傅嫡(dí )女沈宛宛与宁国侯世(shì )子萧至大婚在即,萧至(zhì )的青梅赵(zhào )茵儿(ér )将正室嫁衣换成妾室(shì )粉色嫁衣(yī ),当众(zhòng )羞辱沈家。萧至偏袒赵(zhào )茵儿,让沈宛宛(wǎn )忍让。沈宛宛不甘受辱(rǔ ),借皇上赐婚之机,改嫁给萧至驻守边(biān )关的兄长萧宸,助萧宸(chén )取而代之(zhī )成为(wéi )世子。赵茵儿自食恶果(guǒ )沦为姨娘,萧至(zhì )失势后自甘堕落,竟勾(gōu )结二皇子与北(běi )狄通敌,暗害萧宸。沈宛(wǎn )宛与萧宸将计就计,大(dà )破北狄,揪(jiū )出萧(xiāo )至与二皇子罪证。最终(zhōng )萧至被斩(zhǎn ),奸人(rén )伏法,二人镇守边关,安(ān )稳度日。