Candy Lo does double duty as twin sisters Lok Ling and Lok Yan. A grainy flashback reveals that the two were separated when only nine years old, with Yan going with her father to Shenzen, where he climbed the corporate ladder and gave Yan a decent upbringing and a solid future. Ling, on the other hand, was taken to Hong Kong by her mother, who soon died, leaving Ling to face an unfortunate life without any sort of parental guidance.