Melanie is no ordinary girl. She spends her days locked away in a cell and her only clothes resemble those of a prison inmate. On the few occasions she is let out of her cell, she must be secured into a reinforced chair with head, arm leg and feet restraints. Melanie isn't the only one who lives like this, she is part of a small class where each child is subject to the same treatment as Melanie. The children live on an army base and have been infected with a fungal disease that's spreading far and wide around the world. Whilst the children are infected, they also display human-like characteristics and emotions which is unlike the rest of the infected beings on roaming the outside world.
Outside of the army base, there are few who aren't infected. The soldiers, Dr. Caroline Caldwell and their teacher, Helen Justineau, are the only ones who come in contact with the children and they are subject to deeply disturbing tests. The only humane person in their life is their teacher, Helen. Though she knows how dangerous the children are, she still has affection for them and looks after them and teaches them to the best of her ability in such limited circumstances. Melanie and Helen are particularly close; out of all the children, Melanie appears to be the most adjusted and lashes out at humans less than the other children.
The army base finds itself under attack by some of the infected humans (known as Hungries) a battle breaks out between the humans and the mutated peers and Melanie and Helen find themselves thrown together. Melanie saves Helen from being attacked and equally, Helen protects her favourite student from the onslaught of Hungries.
The doctor, Sergeant Ed Parks, Helen, Melanie and Private Kieran Gallagher escape with little else than their lives. Despite Helen's pleas, the other members of the group are unsure what do with Melanie as they know how dangerous she could be. The doctor has intentions of using the little girl to develop a vaccine but first of all the group must find a new safe place to live.
Starring: Gemma Arterton, Sennia Nanua, Glenn Close, Paddy Considine, Dominique Tipper, Anamaria Marinca, Fisayo Akinade