Recognizing the destructive power of its captive giant Ape, the military makes its own battle-ready A.I., Mecha Ape but its first practical test goes horribly wrong, leaving the military no choice but to release the imprisoned giant ape to stop the colossal robot before it destroys downtown Chicago.。周星星圆满完成了校园任务后,以为可以升职,偏偏被调为交通警察。跟他一样立功的曹达华则继续以卧底的身份在学校内调查国际恐怖组织的案件。他的事业跌到了低谷,就连准备婚礼的钱都是女友阿敏的私房钱,令阿星十分无奈。为了证明自己的能力,他决定以个人的身份到学校协助曹达华,恐怖分子如期行动,双方开始奋战。。