The Mercy Falls Children’s Hospital is about to close its doors for good after one century of service. But the closing process is taking longer than expected; a railroad accident has left the local hospitals without beds. Most of the personnel have left and practically all the installations have already been dismantled.
Amy (Calista Flockhart), a nurse, is sent from London to help. But she soon detects something odd in this place... The children are nervous. And afraid, of something intangible, invisible. Some of them call it "the mechanical girl."
They claim it lives upstairs, on the third floor. The floor that has been closed for 40 years. Little by little, this presence begins to make itself increasingly evident. Because this hospital holds a secret. Something terrifying that has returned from the past. Something that shouldn’t be here. To protect the kids, Amy must face the rest of the hospital staff who refuse to accept the obvious. But the truth is far from what anyone suspects. Darker. More sinister. And more dangerous...