In the year 1936, a new party member accidentally discovers secret information that triggers the Xi'an Incident, thus beginning a story of infighting and schemes. When he was young, Wu Zhong Ming was separated from his older brother Wu Boying by kidnappers. He joins the Communist Party later on and gets captured during one of his missions. His older brother tries to rescue him but dies in his stead. This happens during a time before the Xi'an Incident, and the city has turned into a crucial place for vital intel. To win the final victory, the Communist Party sends Wu Zhong Ming to go undercover as his twin brother Wu Bo Ying and infiltrate the Kuomintang. (Source: ChineseDrama.info) ~~ Adapted from the novel "Infiltrate" (潜伏) by Ma Ying.