During the War of Liberation in 1948, the company commander Gu Zidi (played by Zhang Hanyu) led 47 soldiers of the Ninth Company to perform the task of covering the retreat of the large forces on the banks of the Wen River. The head of the regiment, Liu Zeshui (played by Hu Jun), ordered to retreat as soon as the assembly number sounded. The tragic war began with the roar of artillery shells. The soldiers of the Ninth Company suffered heavy casualties. Platoon leader Jiao Dapeng (played by Liao Fan) said before his death that he heard the assembly number, but Gu Zidi himself did not hear it, so he decided to defend his position. The Ninth Company repelled the enemy's three attacks, blew up two tanks, and annihilated countless enemies. Except for the company commander Gu Zidi, all 47 people in the company were killed. This war changed Gu Zidi's life. Because the troops changed their numbers, Gu Zidi could not find the organization, and the martyrs who died in the Ninth Company were also considered missing. Gu Zidi began a difficult search to seek an explanation for the brothers of the Ninth Company and to find out the truth about the assembly number that year.