In a hospital dominated by ego and corruption, an enigmatic but brilliant surgeon arrives — taking on seemingly impossible cases amid fierce opposition.

Seo-jin, a renowned photographer, is shattered by the sudden and mysterious death of her twin sister and sets out to uncover the truth. As her investigation deepens, an unseen presence begins to close in, twisting reality and driving her into a spiral of paranoia as her vision fades away. Now trapped in encroaching darkness, Seo-jin faces a terrifying revelation that shatters everything she thought she knew.

A man and woman who were in love in their 20s meet again in their 40s, and find that they've both become different people during their years apart.