30 years ago, rich young ruler Yip Sung-Nee (Tan Soo Seng) assaulted his pregnant employee Cheng Man-Yuk (Hong Hui Fang). He also caused Yuk's father to die a tragic death, further angering Yuk. Both Nee and Yuk later had baby girls in the same hospital, but due to the hospital's negligence, the identities of the babies were swapped. Yuk discovers that her biological daughter suffers from heart disease. Knowing that the girl would receive the best medical care, coupled by her hatred against Nee, she kept quiet about the identity swap. The destinies of the two girls Sum (Zoe Tay) and Kiu (Fann Wong) are changed forever.
As the secret of the past catches up with them, the stage is set for vengeance and destruction.