Two old comrades who fought side by side on the battlefield are now working on the railway front after liberation. They clash due to differences in ideas and management methods. In the end, they learn from the advanced ideas of the Soviet Union to defeat conservative old ideas.

Young technician Lu Ye changes his minds about Shanghai girls during the work with inspector Bai Mei --a girl from Shanghai.

时值抗日战争时期，铁路工人李玉和（浩亮 饰）肩负着接应地下党交通员的重任。女儿铁梅（刘长瑜 配音）年纪虽小，却耳濡目染，与这个没有血缘关系的爹爹和奶奶（高玉倩 饰）具有同样的爱国情怀和革命热忱。是夜，携带重要密码的交通员被迫跳车，遭日寇枪伤。李玉和将其背回家中，却未能挽救他的性命。另一方面，日本宪兵队队长鸠山（袁世海 饰）奉命展开全城大搜捕，势要找到那份至关重要的密电码。关键时刻，革命队伍出现叛徒，鸠山将目标锁定在李玉和身上，为了找到密电码，残酷的敌人无所不用其极。而李氏一家三代也迎来了最为严峻的革命考验…… 该剧根据电影《自有后来人》改编，为文革期间八个样板戏之一。