Narrator of the story: A villager dumbly recalled that in 1974, China was in the late stage of the Cultural Revolution, a series of past events in a village. The Xiangyuan family suddenly caught fire and his wife was burned.

Wei Junlan, who retired from the Municipal Food and Drug Administration, was suddenly murdered, and her tragic death at home shocked the whole city. On the surface, her husband, Qin Yaxuan, was heartbroken, but it was discovered that he had long been separated from his wife, and that he had been in close contact with a young and beautiful single woman, Wu Tong. However, the absence of the two also prevented the police from concluding that love was the motive. When the case was at a loss, drug dealer who once had a feud with Wei Junlan, became a new target of suspects.

An old man finds it hard living with his injured legs, having to depend on others for his needs. But when a small puppy escapes from a nearby dog meat restaurant and comes into his life, things start to turn around.

In the Korean War China and North Korea fought together against the United States. Frontline needs in tens of thousands tons of military supplies every day. Railways has become the most important means of transport. The U.S. Army, unwilling to accept defeat on the battlefield, mobilized a large number of aircraft to bomb indiscriminately along railways, and carried out the so-called "war of attrition". Following the order of Commander Peng Dehuai, Liang Junying, the commander of the Sino-DPRK Joint Railway Transport Command, led the volunteer warriors on the transport front to carry forward the fearless revolutionary spirit, building bridges, repairing railways, and transporting supplies in the "317" section, which was dotted with bombs and mines. This is the real "indestructible and bombable steel transport line".