Happiness - Season 1 - Eps 4: The Spread
The apartment complex gets walled up and quarantined due to Min Ji's mad person disease triggered by the Next drug. Whether they like it or not, the people living in the apartments have to stay within the walls together for a week. Sae Bom and Yi Hyun isolate the suspect Ju Hyung and provide shelter for outsiders. Meanwhile, during the joint investigation, Yi Hyun and Tae Seok discover the dealer of Next lives in Building 101.
About Happiness

Title: Happiness
First Air Date: 2021-11-05
Last Air Date: 2021-12-11
Status: Ended
Rating: 8.1/10 (from 497 votes)
Language: KO
Seasons: 1
Total Episodes: 12
Network: tvN
Genres: Drama, Mystery, Sci-Fi & Fantasy
Production Companies: Studio Dragon
Synopsis
A new type of deadly virus spread throughout the city, and the apartment where has different social classes of people is sealed off. With the fear of the virus, and the conflicts of the different classes, the residents have to spend and survive in the new habitation.
Cast

Han Hyo-joo
Yoon Sae-bom

Park Hyung-sik
Jung Yi-hyun

Jo Woo-jin
Han Tae-seok

Lee Jun-hyeok
Kim Jeong-guk

Park Joo-hee
Lee Ji-soo

Bek Hyun-jin
Oh Joo-hyung

Baek Joo-hee
Park Min-ji

Moon Ye-won
Woo Sang-hee

Park Hyeong-su
Kook Hae-seong

Jung Woon-sun
Shin So-yoon