During the 2nd Sino-Japanese War, orphan Lu Feng returns to Shanghai as a Communist undercover agent, tasked with infiltrating No. 76 Headquarters. There, he crosses paths with the mysterious Hua Xiang Yu and his childhood friend Huo Fei, both hiding secrets of their own. As they circle each other in a dangerous game of loyalty and deception, these hidden agents must decide what they truly stand for, risking everything to fight for a better future.

该剧以全景式展现红军长征这一波澜壮阔的历史画卷，呈现一个个有血有肉有温度的革命故事，弘扬伟大的长征精神。
1934年，日本帝国主义加紧了对中国的侵略，而蒋介石不顾民族危亡，坚持“攘外必先安内”的政策，发动了规模最大的第五次“围剿”。生死存亡之际，中国工农红军主力被迫实行战略性转移，撤离长江南北各苏区。平均年龄不到30岁的红军队伍犹如一条条红色铁流，经过11个省，翻越18座大 山，跨过24条大河，走过荒草地，翻过雪山，行程二万五千里。直到1936年10月红军三大主力会师，红军长征胜利结束。

Black Girl is a deaf-mute prisoner. Prison guard Deng Hong found White Fox, a prisoner who understands sign language, to supervise her transformation. The two made money together after serving their sentences, met Deng outside the prison.

On the day of the 1949 Founding Ceremony, Xiao Dali (Lei Jiayin), who has just entered the city to be reorganized as the head of the public security police station, discovers that Feng Jingbo (Hu Ge), an elementary school teacher, is suspected of being suspicious. With the high alertness of a soldier and the sense of responsibility of a public security warrior, he is hard-partnered with Feng Jingbo as a neighbor, exhausting his life through trials and tribulations, and carrying out a nearly four-decade tracking without complaint or regret. The movie is based on Zhang Ce's novel.