Infection

In a rundown hospital, Dr. Akiba refuses to admit a patient with a strange black rash. Soon, Room 3's burn victim dies after receiving the wrong drug. The crisis hints at a cover-up that is already taking shape.

Akiba teams with Dr. Uozumi and four nurses to hide the death and move the body to an unused room. They hope to avoid investigation and accountability.

The head nurse discovers that the patient Akiba refused to admit has been left in the hallway. She immediately informs Akiba of the alarming oversight.

Akiba learns that Doctor Akai has taken the patient and is studying his symptoms. The patient is alive, but his body mass is liquefying into green goo.

Despite warnings, Akiba and the others reluctantly help examine the patient. The condition worsens as the green substance continues to spread.

The patient vanishes from the room, and the head nurse falls unconscious.

The head nurse wakes and begins bleeding green goo from her ears and eyes as infection spreads. The mean nurse and the young nurse escalate into chaos: the young nurse draws blood on herself, laughs maniacally, and stabs two needles into her body, splattering green goo on the other nurse.

Uozumi, burdened by guilt over a patient he helped kill earlier, becomes infected. His eyes turn white and green goo seeps from him.

The infected mean nurse hangs upside down, spreading fear through the ward. Akiba bolts from the room as the outbreak escalates.

Akiba confronts Akai, accusing him of creating and spreading the infection. Akai denies responsibility and explains that the infection spreads mentally, infecting the subconscious.

Dr. Nakazono arrives and forces Akiba to realize he has been speaking to his own reflection. She sees the corpses of the two nurses, dead and without any green goo, and suspects a hallucination.

Nakazono calls the police as Akiba recalls the events in Room 3 and realizes that Akai was the burn patient. The truth begins to surface behind the nightmare.

The same sequence of events is shown again with swapped identities, revealing that Akiba was the burn patient and Akai the one who ordered the wrong drug, massacring the staff.

The hospital is evacuated the following day as all staff except Nakazono are dead. The police search for Akiba who has disappeared.

Nakazono leaves the hospital as red lights flip to green and she panics, cutting her hand and green blood pours out. A locker in the burn victim's room opens, and Akiba's hand, covered in goo, reaches out before falling to the floor.