Based on a novel by Gu Long, Frankie Chan's A Warrior's Tragedy details the parallel stories of two warriors: one trained to love, the other to hate, both to be superior swordsman. On one side of this twisty tale of murder and revenge lies the dark and brooding Fu Hung-Suet (Ti Lung). Dressed from head to toe in basic black, Fu wanders from town to town, dispatching his enemies with his impressive ebony sabre. On the other end of the spectrum is the happy-go-lucky Yip Hoi (Frankie Chan), a cheeky, mustachioed fellow who dresses in white and happens to be a proficient martial artist. As one would expect, the two contrasting swordsman are locked on a proverbial collision course with destiny as both are invited to the home of the villainous Ma Hong-Kwan, who has a sinister connection to our heroes.

艾利克斯（张智霖 饰）从小和母亲（叶德娴 饰）相依为命，母亲辛辛苦苦的抚养他长大，最终将艾利克斯培养成为了一名出色的广告制作人，对于儿子的成就，母亲倍感自豪。成年后，艾利克斯娶了名为蓝晓彤（袁咏仪 饰）的妇产科医生，恩爱的两人婚后生活十分幸福。
然而，灾难还是降临了，艾利克斯在意外中受伤，生命垂危，临死之前，艾利克斯终于向蓝晓彤坦白了内心里深藏多年的秘密，原来，他有一个秘密情人小黑（何超仪 饰），并且，小黑的腹中已经怀上了自己的骨肉。艾利克斯希望母亲和妻子能够接纳小黑及其腹中的孩子，这让震惊的蓝晓彤陷入了道德与情感的困境之中。