1946年，八年的艰苦抗战终于结束，而国共两党则旋即拉开内战的大幕。蒋介石调动二十万大军对解放区发起猛攻，其后国军又以五十万大军进攻苏皖，内战局势进入了关键时刻。连番激烈的炮火过后，李先念率领的主力部队转入豫鄂陕地区，曾经好不容易巩固下来的大别山再被敌人夺去。在此危机时刻，许多人的内心发生了动摇，革命立场产生动摇。县委书记和县委组织部长莫文阶不过多久叛变革命，游击队员南果祥也开始产生畏惧敌人的情绪。 　　黎明前的五更天，冰冷刺骨，肃杀阴森，闯过了这道难关便是朗朗的艳阳天，在这过程中又有多少人能坚定信念，迎接胜利的到来……

In 1946, Chiang Kaishek commits 200,000 troops to an attack on the Communist-held central plains of China. After the PLA main force in the area retreats, the Nationalists also capture the area around the Dabie Mountains. County Party Committee Secretary Liu and county organizations department director Mo Wenjie lead a guerrilla troop against the KMT forces. Will the film belief of the revolutionary cadre be able to overcome not only the enemy, but cold, hunger and betrayal?