The film takes place in an under-staffed hospital that is quickly losing money. In the middle of the night, an ambulance comes to the hospital with a patient with a strange black rash. Dr. Akiba refuses to admit the patient, due to the fact that the hospital is low on resources and staff. While arguing with the paramedic, Akiba is alerted to a serious crisis in the hospital's room 3. A patient, though unconscious, has somehow fallen to the floor and his vital signs are dropping quickly. They think they have saved him when they realize that the nurse has apparently misheard "chlorate" instead of "chloride" and injects the wrong drug into his IV. The present staff members, Doctors Akiba, Uozumi and four nurses, after a long and harsh argument, decide to cover up the true cause of his death and say that he died naturally.
Soonafter, Dr. Akiba discovers that the patient he rejected earlier has been left in the ER. The patient is apparently carrying some sort of extremely dangerous pathogen. Another doctor, Akai, makes his presence known and suggests that they study the symptoms of this patient. Not knowing how much Akai knows about the events in room 3, the other doctors reluctantly agree, only to find that the disease carried by the unknown patient is incredibly contagious and lethal, killing very quickly. Akai's suggested threat to uncover the other staff members' malpractice forces them to stay in the infected hospital until the bizarre true nature of the disease is revealed to Akiba
