Trapped in an apartment with zombies that still think

A residential building is placed under isolation when a zombie infection starts spreading between residents, but the situation worsens after they uncover a serial murderer living among them.

The Title: Happiness

Cast:

Han Hyo-joo as Yoon Sae-bom
Park Hyung-sik as Jung Yi-hyun
Jo Woo-jin as Han Tae-seok
Lee Jun-hyeok as Kim Jung-kook
Park Joo-hee as Lee Ji-soo
Baek Hyun-jin as Oh Joo-hyung
Moon Ye-won as Woo Sang-hee
Park Hyung-soo as Kook Hae-seong