Dr. Jung Se-ok is a brilliant but disgraced neurosurgeon haunted by a past tragedy. Stripped of her medical license, she performs illegal surgeries in the shadows, driven by an insatiable thirst to push the boundaries of neuroscience. When her path crosses that of her former mentor, the famed but enigmatic Dr. Choi Deok-hee, old wounds are reopened and a dangerous game of power and revenge erupts. As Se-ok delves into groundbreaking but ethically questionable procedures, she struggles with the moral consequences of her actions, blurring the lines between medical necessity and personal ambition.