Na Yi-je is a brilliant yet ruthless doctor, a master manipulator who bends the system to his will. Once framed and imprisoned, he has risen to power by outsmarting corrupt officials, taking over as the new medical director of Seoul Penitentiary. Known as the "Night Doctor," he secretly helps powerful criminals escape prison through fabricated diagnoses while plotting revenge against those who wronged him. With his sharp intellect, unshakable composure, and undeniable charisma, he commands.