中越边境，以副连长、一排长为首的九人集体，冒着敌人的密集炮火来到三号哨位——一个天然山洞，开始了三个月艰苦的战斗生活。先是闷热，没有水。疾病和潮热时刻威胁着战士们，但他们仍保持乐观的精神。长期缺阳光、缺营养、缺睡眠，使战士们全染上了疲劳综合症。副连长回忆起后方烈士的妻子严萍萍，在丈夫死掉后坚强的活下并抚养起烈士的后代。小顾不幸触电身亡。战士们背着小顾，走在红色的泥浆地上。副连长和严萍萍在一排皮墓碑前寻找烈士的亡灵。

At the Sino-Vietnamese border, a group of nine people headed by a deputy company commander and a platoon commander braved the enemy's intensive artillery fire to the No. 3 post, a natural cave, and began three months of hard fighting.