Adapted from Zhou Meisen's novella "Military Song." In the early stage of the Sino-Japanese War, after several major battles, the Japanese army captured a large number of Chinese prisoners of war. Among these prisoners were members of the Central Army, makeshift forces, and a few soldiers from the Eighth Route Army. They were all forced into the "Ninth Death Camp" established by the Japanese army. Old scout Tian Desheng and Liu Ziping from the Central Army, along with Eighth Route Army cavalry battalion leader Meng Zexin and soldier Zhang Delong, were locked in Cell No. 4. In Cell No. 4, a group of prisoners led by the Sichuan Army battalion commander Old Qi was secretly planning to break out of the death camp. Using their labor in the coal mine, they constantly sought opportunities to enter old tunnels to scout for a route, hoping to find a way to escape. Meanwhile, another group of prisoners led by Meng Zexin was also preparing to escape. Although both groups had the same goal, they did not trust each other and acted independently. The commander of the death camp, Long Zeshou, was a ruthless and cunning Japanese Army captain. To provide more coal for the invading Japanese forces, he not only assigned collaborators to deal with the prisoners but also looked for informers among them. Soon, Old Qi was reported by a collaborator. Long Zeshou gathered all the prisoners and unleashed guard dogs on Old Qi, who was mauled to a bloody pulp. To rescue all the prisoners in the death camp, the guerrilla team sent Zhang Mazi to infiltrate...