Northern Lights Insurance Company has a team of insurance investigators that is led by Fong Chi-Keung, the wealthy heiress Do Sam-Yu, the affectionate Bak Tin-Ming, and retired police officer Cheung Dong. They each have their own talents and they form a legendary team in the insurance industry. They thoroughly investigate and uncover the truth in all thorny, dangerous or strange cases that are passed to them.

Guardian Angel ran for 1 season. No new episodes are scheduled.