The Hera Palace is a luxury penthouse apartment dubbed as the castle for the richest one percent. With 100 floors, it’s a commanding structure that beams of opulence. However, within this expensive piece of real estate are many secrets and hidden ambitions. 

Shim Su-ryeon (Lee Ji-ah) is a woman born to wealth and is considered the queen bee of the penthouse. Despite being surrounded by all the glitz and glam, Su-ryeon still couldn’t escape the shadow of a tragic past. She is married to Joo Dan-tae (Uhm Ki-joon), a successful businessman who has been hiding a secret from her. 

Cheon Seo-jin (Kim So-yeon), is the prima donna of the lot. She is a famous soprano whose father heads the prestigious Cheong-ah Arts School. 

Oh Yoon Hee (Eugene) comes from a poor family background but she works hard so she can be part of high society. She wants to be the queen of the penthouse because she believes that it’s one of the true definitions of success. However, that leads her to cross paths again with Cheon Seo-jin, her mortal enemy.

Their lives take a twisted turn when a young mysterious girl named Min Seol-ah (Jo Soo-min) fell to her death during a party at the Hera Palace. While the residents try to cover it up, they can’t help but suspect if any one of them is behind it.