After they return from their mission of obtaining food, the people inside won't believe anything they say about what they saw. Everyone starts to doubt each other, and distrust builds up among them as they hide their true feelings. Meanwhile, the personal trainer locked up in the fitness center turns into a monster, putting fear in the people of the building.
Elenco: Han Hyo-joo , Park Hyung-sik , Jo Woo-jin , Park Joo-hee , Lee Ji-ha , Bek Hyun-jin , Park Hyung-Soo , Han Da-sol , Park Hee-von , Moon Ye-won , Kim Young-woong , Na Chul , Cha Soon-bae , Lee Ju-seung , Han Jun-woo , Yoo Ji-yeon , Bae Hae-sun , Kang Han-saem .