Twenty years ago, an operation causes pediatric trainees Fong Chung-yan and Hui Kam-fung to become foes. Now Chung-yan is a consultant pediatric surgeon at a top hospital. He and Kam-fung, who is employed by a second-tier hospital, meet up again due to a liver transplant operation. Chung-yan coaxes Kam-fung into joining his elite team. He even invites cardio-thoracic surgeon Cheung Yee-sum and Chief of Service, Surgery Mak Hoi-kei to pave the way for building a pediatrics center. Chung-yan and Kam-fung also gradually put their differences aside as they repeatedly play certain roles in touching and sometimes tragic stories about sick children. Meanwhile, pediatric surgeon Man Pak-hei and anesthesia trainee Lin Cheuk-ying find out that particular operation performed all those years ago was associated with some medical blunder. They wonder whether they should reveal the truth.