Choi Do Hyun (Lee Jun-ho) spent most of his childhood in the hospital due to a serious heart condition. Finally, thanks to a series of fortuitous events, he was given the chance to receive a transplant. Shortly after the surgery, his father becomes implicated in a murder, is put on trial, and sentenced to death. Following this, Do Hyun passionately studies law, becomes a skilled attorney, opens his own firm, and, in the meantime, investigates the many murky aspects of his father’s case.