Black Jack survives the shooting because his mother's pendant stopped the bullet. He operates on Dr. Bart’s mother, Catherine, and discovers that she has a Type Hydra artificial heart which keeps beating even when it is extracted from the host. Jack replaces the Type Hydra with another artificial heart and saves her life. They discover that the Type Hydra was designed by Jack's father, Hazama Kagemitsu, through a microfiche that was inside Mio's pendant...