A group of communist guerillas encounter jealousy and rivalry among themselves because of the presence of the female compatriot while one of their members plots to desert their band.

It is a dramatization about Major Kim Man-il's service during the Korean War. The Korean forces dispatch two military units to defend the Baeti Heights led by Kim. Although it is hard to do so, Kim and his senior, Kim Mu-cheol (Choe Bong), and other soldiers do their best. Kim even risks his life to save his juniors, but many die as the enemy forces approach. Meanwhile, Lee Kang-no (Yun Il-bong), a communications officer, reads a letter from his wife - missing her and his daughter. Encouraged by it, Lee risks his life to make successful communication between his military unit and the headquarters. His unit wins. Commander Kim Man-su gathers a small number of his subordinates because many had died, and encourages them to do their best toward the enemy off.