What 2021 South Korean apocalyptic thriller series follows residents of a newly built apartment complex as they struggle to survive and retain their humanity during the outbreak of a deadly infectious disease?

The 2021 South Korean apocalyptic thriller series that immerses viewers in a newly constructed apartment complex during a deadly outbreak is titled "Happiness (Review)." This captivating series follows the residents as they navigate a terrifying new reality, struggling not only for survival against a rapidly spreading infectious disease but also to preserve their humanity amidst escalating fear and distrust.

Set in the near future, the show introduces the "Lytta Virus," also known as "mad person disease," which causes infected individuals to experience bouts of insanity and bloodlust, eventually regressing into a zombie-like state. The series cleverly uses the confined setting of the sealed-off apartment building to explore themes of class disparity, human nature, and societal collapse. As supplies dwindle and the threat outside looms, the true characters of the residents emerge, revealing both the best and worst aspects of human behavior under duress.

"Happiness" distinguishes itself from typical zombie narratives by emphasizing psychological tension and social interactions over excessive gore. It centers on a special operations unit officer, Yoon Sae-bom, and a detective, Jung Yi-hyun, who find themselves caught in the lockdown and strive to protect those around them. The drama offers a compelling commentary on how collective anxiety and adversity can expose the fragility of social systems and the inherent selfishness and greed that can arise when survival is at stake. Originally airing on tvN, "Happiness" gained significant global attention upon its release on various streaming platforms, becoming a sleeper hit and earning praise for its engaging plot and the chemistry between its lead actors.