Happiness Ending explained: Does Park Hyung Sik as Yi Hyun die as a zombie?

Happiness' finale was a tumultuous ride that brought Sae Bom (Han Hyo Joo) back to her apartment after Han Tae Sook figured out that there was another man who had developed the antibodies. In Episode 15 of Happiness, it became clear that Yi Hyun (Park Hyun Sik) was infected.

He had begun to feel thirsty, and the infection had left him worried for Sae Bom's safety. He managed to send her out with Se Yeon, the little girl they were taking care of. However, he decided to remain in the apartment.

---

Who did Yi Hyun bite for the first time in Happiness?

Yi Hyun sent his partner detective, Sae Bom, Se Yeon and Bo Ram along with another resident of the apartment out to be taken care of by Han Taek Sook. However, Andrew, who was revealed to be a serial killer in an earlier episode, tried to stop them from leaving. He even shot Yi Hyun in the process.

In anger, Yi Hyun transformed into a zombie and bit Andrew. The one who witnessed this was none other than Yeon Ok. She was not infected, however, she tried her best to use the situation to her advantage. She tried to convince the residents of the fifth floor that Yi Hyun was infected so they needed to stay away from him.

However, because of the help that the residents received from Yi Hyun, they did not mind giving him some space and time after being infected.

---

Where did Sae Bom find Yi Hyun in the finale of Happiness?

Meanwhile, Sae Bom received one shot of the cure developed from her plasma in Happiness. She held on to it for Yi Hyun, but then decided to administer the cure to Se Yeon's mother. That was because she did not want the little girl to lose both her parents to this infection. She did leave the secret compound with Han Tae Sook and Ji Soo's help.

The moment she arrived at the apartment in Happiness' finale, she checked on Yi Hyun's whereabouts and was happy to learn that he was alive. However, when she arrived at the door, she saw Ju Hyeong act as if he was infected. He first bit the woman he had an affair with for attacking him to steal his money.

He then struck her to ensure she bled and forced Yi Hyun to face the truth of what it meant to be infected. Yi Hyun managed to lock himself in and tried to control the breakout as much as possible. Sae Bom came just in time and kicked Ju Hyeong out of the way. He deserved much more, but Sae Bom's attention was on Yi Hyun.

She saw him shaking in fear and struggling to control his oncoming change under the darkness of a blanket in Happiness. Sae Bom helped Yi Hyun calm down, and confessed her feelings to him. She explained how much she missed him. Her calming voice helped him and when he returned to himself, the two shared an intimate moment together.

Despite all the plans by Yeon Ok and Ju Hyeong in Happiness, Sae Bom managed to get Yi Hyun out. The two also managed to also keep Se Yeon safe. A time skip to a year later shows both Yi Hyun and Sae Bom happily in love, reminiscing about the time they spent together in lockdown.