In January 1949, the Chinese People's Liberation Army besieged the Kuomintang's 500,000 troops in the Pingjin area, and the general offensive was imminent. Whether Peking can be liberated peacefully depends on the Tianjin War. At this time, the city of Tianjin was full of bunkers and fortifications, and the soldiers were armed with live ammunition. The city of Tianjin before the war was already a purgatory. In order to pave the way for the launch of the general offensive, the PLA artillery reconnaissance company commander Cai Xingfu, scout Ma Baoshu, radio operator Liao Feng, and artillery trainee staff Ge Guichen were ordered to form the Liberation Artillery Reconnaissance Rangers and sneak into Tianjin in disguise. At this time, Yao Zhe, the Kuomintang quartermaster responsible for transferring the dependents of the Peking garrison, became a wanted criminal under the conspiracy of Qian Zhuoqun, the military police battalion commander. When he fled with his daughter, he happened to meet Cai Xingfu and his group who entered the city. Cai Xingfu held Yao Zhe hostage to complete the task. As the target tasks gradually became clear, the secrets behind Yao Zhe's conspiracy, Qian Zhuoqun's conspiracy to sabotage the Peking peace talks, and the whereabouts of Cai Xingfu's missing son gradually emerged...