(idiom) to do something under cover of a diversion or to engage in secret activities by deceiving others with false appearances, based on a military strategy used by [[刘邦|劉邦|liu2 bang1]] against [[项羽|項羽|xiang4 yu3]]

To do something under cover of another activity; to maintain a secret relationship or conduct an illicit affair

Chencang District of [[宝鸡市|寶雞市|bao3 ji1 shi4]] in Shaanxi province

to feign an advance along a main route while secretly taking a detour to strike by surprise; using a deceptive front to cover a hidden agenda

Literally meaning to repair the plank road by day while secretly crossing at Chencang, this idiom describes using a diversion to hide one's true intentions or activities.