国家庆典前一天，首相突然失踪了，与他最后接触的安全局长邱启贤於是成了嫌疑犯。邱启贤的女儿、同样为安全局一员的邱默语(柯佳嬿 饰)为了替父亲洗刷冤屈，带著首相女儿艾心至「龙门城寨」，希望能找到证据替证明父亲清白。

　　邱默语的青梅竹马周怀安(王阳明 饰)原在国外受训，为此赶回国同样到了「龙门城寨」。城寨的主人金湘玉(陈怡蓉 饰)，一个风骚多情身上充满秘密的女人，加上西区警探小刀(谢佳见 饰)，这四人聚首於「龙门城寨」，将发展出一段爱恨情仇。 究竟谁才是绑架首相的凶手？四人感情如何纠葛？

Qiu Mo Yu is an agent assigned to protect the president's daughter. Her father is suspected of colluding against the president in a terrorist attack. She is determined to prove her father's innocence by investigating the disappearance of the president. She and her lover, Zhou Huai An tackle the case but get involved with some shady characters - Jin Xiang Yu, who is the lady boss of the underworld and Xiao Dao who is a cop that might've gone rogue. Mo Yu and Huai An find themselves getting deeper into something that they never expected.