In Country A, Zhao Jian leads his Black Wolf Squad to escort cargo for General Cha Cai. They are ambushed by guerrillas. Zhao Jian captures the guerrilla leader Zhang Ling and learns that the Black Wolf Squad isn't transporting humanitarian supplies but materials for human experimentation conducted by Cha Cai for personal gain. Zhang Ling pleads for help from the Black Wolf Squad but is refused. On their way back, the squad stumbles upon the horrifying aftermath of the human experiments in the jungle. Overcome with sorrow, Zhao Jian decides to quit the Squad and join Zhang Ling to fight Cha Cai. Zhao Jian is backed by his teammates, who vow to wipe out Cha Cai's organization and avenge the dead.