Kim Se Hoon, the guy on the 15th floor, goes missing. Sae Bom and Yi Hyun try to figure out why he disappeared and what he was trying to hide….

Mr. Gu brushes Mi-jeong aside, but she sees straight through him — his guilt, his fears, and his habit of deserting happiness when it’s within reach.

The residents in Building 101 suspect Sae Bom and Yi Hyun are infected and quarantine them in their unit. With them quarantined, the residents discuss what to do about them….

The apartment complex is now without electricity. Sae Bom and Yi Hyun find traces of an infected person inside Building 101. Who could be infected? The residents suspect others of…

The apartment complex gets walled up and quarantined due to Min Ji’s mad person disease triggered by the Next drug. Whether they like it or not, the people living in…

Molly takes Andrew to a work function and they struggle to see eye to eye. Issa continues to search for happiness. The girls get a distressing call about a friend.

At Luke and Manny’s first school dance, Jay and Phil take them to the mall which turns disastrous, Claire’s happiness turns into jealousy when Gloria joins the school dance committee….