抗战期间,为打击汪伪政府特务组织76号,军统成立新安特训班。情胜兄弟的发小陈克海和方黎结伴前往,以期抗日救国。然而一次任务的失利却让陈、方二人天各一方。两年后,已秘密加入共产党的陈克海回到上海并潜入76号,发现方黎已经站在了自己的对立面。兄弟重逢之际亦是道路抉择之时。面对性格大变的陈克海,方黎屡次试探,甚至不惜欺瞒以确定陈克海的身份。陈克海身处敌营,虎狼环伺,面对一次次的试探与危机,他临危不惧,化险为夷,为组织输送了宝贵的情报。但他发现方黎的身份似乎也并不简单。战局的迷雾渐渐散去,这对昔日的同窗知己,为了彼此的信仰,将迎来最后的对决。
Childhood friends Chen Ke Hai and Fang Li went their separate ways and found themselves in the No. 76 secret service. In 1939, the Bureau of Investigation and Statistics created a special class to combat the No. 76 of Wang Jing Wei's regime, with the hope of resisting Japan. Chen Ke Hai, now a secret member of the Communist Party, returns to Shanghai with the mission of infiltrating No. 76, where Fang Li is the leader. The brutal experiments reveal the truth about the bureau. Chen and Fang are separated after a failed assassination attempt. Facing a drastically different Chen Ke Hai, Fang Li tests him and places an agent at his side. Chen Ke Hai struggles to convey valuable information to his party without backing down. After the war, the former colleagues have a final confrontation over their contrasting beliefs.