When dentist Park Mu-hyun decided to live in the underwater station known as the North Pacific International Undersea Base (NPIUS), he anticipated a quaint and quiet life in the deep sea. But five days into his new home, the living quarters begin to leak. In fact, the entire station has been plunged into disarray after being attacked by a mysterious group! With only moments to act, Park Mu-hyun grabs his backpack and begins to make a run for it. Even though he has no idea where to go or what to do, Park Mu-hyun must navigate the once peaceful station and survive the madness and havoc that has befallen the residents. Between crazed cults and deception at every turn, can Park Mu-hyun find a way out?