The quiet life of an extreme introvert is thrown upside down when his company hires a cheery and outgoing new employee who's not all she seems.
EPISODE 1
The Phantom of the Opera
Chae Ro-un, newly recruited and a little suspicious, has a goal to get through the restricted area and approach Eun Hwan-gi, the secret man covered in a veil.
EPISODE 2
I'm Sorry, I Cannot Apologize
Hwan-gi finds out the person who outed him was Ro-un; Woo-il gives an unexpected suggestion.
EPISODE 3
I'm Not An Easygoing Person
Hwan-gi is caught up in chaos when the penthouse is covered with other people's footprints; he is mistaken as a psychopath, incapable of communicating with others, and is excluded from his employees.
EPISODE 4
I Won't Meet Anyone
The introverted boss commands an absurd task; the task is to not say anything and to not see anyone; Ro-un digs into the real Hwan-gi.
EPISODE 5
The Unspeakable Secret of 3 Years Ago
Revealing the secret behind why Hwan-gi had to become a ghost of the penthouse three years ago.
EPISODE 6
How Does a Person Change?
Hwan-gi's embarrassing presentation video goes out; after creating a mess in the penthouse, all members of Silent Monster are on the verge of getting fired.
Yeon Woo-jin
Park Hye-soo
Yoon Park
Ye Ji-won
Heo Jeong-min
Gong Seung-yeon
Lee Jin-ho
So Jaehyun
Joo Hwa-mi