Years later, in Shanghai, Szeto (Liu Ye) and Tang Yiling (Li Bingbing) have fallen in love. Cynthia has also returned to Shanghai now as a member of Purple Butterfly, a powerful resistance group against the Japanese occupation, led by Xie Ming (Feng Yuanzheng). After a case of mistaken identity and a shootout at a railroad station that leaves Yiling dead, Szeto finds himself an unexpected pawn in the battle between former lovers Cynthia and Itami who has also come to Shanghai, now as a member of the Japanese secret police unit tasked with dismantling Purple Butterfly.