In the fifth episode of Happiness , titled "The Outsiders," residents of Building 101 face a total communication lockdown and dwindling resources, forcing a dangerous mission for supplies. Yoon Sae-bom and Jung Yi-hyun navigate infected threats and internal conflict with other residents, led by the manipulative Oh Joo-hyung. Read a full recap of the episode on The Writers Room . Happiness – Episode 5 Recap - The Writers Room