Xiàng Zhuāng wǔ jiàn , yì zài Pèi gōng
lit. Xiang Zhuang performs the sword dance, but his mind is set on Liu Bang 劉邦|刘邦[Liu2 Bang1] (idiom); refers to 206 BC plot to murder Liu Bang, aka Duke of Pei 沛公[Pei4 gong1] and the future Han emperor, during a sword dance at Feast at Hongmen 鴻門宴|鸿门宴[Hong2 men2 Yan4]
an elaborate deception to hide malicious intent