故事发生在第二次世界大战的最后几个月，《战争之雾》告诉了受伤的美国飞行员吉恩和他的OSS特工未婚妻佩妮回到马萨诸塞州的一处偏远庄园，与佩妮的远房叔叔罗伯特住在一起的故事。在她不知情的情况下，OSS招募了吉恩来监视这个家庭和周围的社区，因为与D日入侵有关的绝密文件被盗，一名敌方内奸就在附近的某个地方，准备将这些计划移交给轴心国。

　　It’s 1945 and Hitler is dead. The remaining Nazi leadership is expected to surrender any day but not all Nazis are in agreement. When the guards of the castle turned POW prison, Castle Itter, flee their post, a group of French political prisoners are forced to defend themselves. Rumors of a rogue Nazi captain hellbent on maintaining the Third Reich threaten the lives of all the prisoners at Castle Itter. With the help of members of the German resistance, a small band of American soldiers, and one Sherman tank, Castle Itter makes its final stand in the final hour of WW2.