An infected person enters Building 101, and once again, Building 101 is under the threat of infection. Lieutenant Colonel Han enters the apartment complex with news to tell, but Sae Bom and Yi Hyun find him suspicious. A person goes missing due to the intrusion, and those with similar interests and minds stay close together.
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 .