For a moment in Happiness, episode 3, Sae Beom (Han Hyo Joo) was worried that she would be locked into her apartment alone. Instead, it led to a momentary heart-felt hug at the end of a shocking episode involving her and Yi Hyun (Park Hyung Sik).
First things first, the show portrayed events before the onset of an apocalypse. It depicted the journey of those who worked hard to stop an apocalypse from happening and that is what led to the apartment getting cordoned off in Happiness, episode 3.
What was the shocking revelation in Happiness, episode 3?
The virus, which was spread among random groups of people, has now found an epicenter in Sae Beom's apartment in Happiness, episode 3. Someone intentionally distributed the drugs within the apartment through one of the peddlers who was investigated by Yi Hyun.
Employed as a gym trainer, he confessed to Han Tae Seok about distributing drugs to many in the apartment.
This truth led to Han Tae Seok 's climactic decision. He had seen the worst when it came to infected people. Happiness, episode 3 revealed that his pregnant wife was attacked by one of the infected and she now lay in a secure facility. There didn't seem to be any cure in sight for such infected people.
With minimal information, manpower and resources, there is nothing else Han Tae Seok could do but shut down the entry and exit points of the apartment. The question now in Happiness, episode 3, is how the apartment residents would survive a breakout without support.
Even as these events unfolded, Yi Hyun was unaware of their fate. He was busy investigating the death of the woman who lived in the apartment above his.
He managed to figure out that the husband had tried to kill his wife even before the infection had spread within her in Happiness, episode 3. He returned to his apartment to make an arrest but ended up being locked inside, along with See Beom.
Sae Beom was glad that she did not have to go through the entire ordeal alone. However, Happiness, episode 3 also hinted at how other people, such as Yi Hyun's partner, might also get stuck inside the apartment.
The episode also indicated that there was someone above the peddlers who instructed them to distribute the drugs among common people. A bag full of banned drugs was found with one of the three peddlers that Han Tae Seok and Yi Hyun had investigated.
The episode also left audiences with important questions. Who was behind Han Tae Seok? Was the government trying to cover up the spread of the infection amongst the public to prevent mass hysteria? It seemed highly doubtful.
The heartfelt moment that was portrayed at the very end of the episode also led viewers to believe that while things are platonic between Sae Beom and Yi Hyun in Happiness, episode 3, their relationship will progress over the next episodes.