Three generations grappling with a life-changing experience during one day of a vacation in Sintra, Portugal, a historic town known for its dense gardens and fairy-tale villas and palaces.

In a dystopian near future, humanity has been ravaged by a mysterious fungal disease. The afflicted are robbed of all free will and turned into flesh-eating 'hungries'. Humankind's only hope is a small group of hybrid children who crave human flesh but retain the ability to think and feel. The children go to school at an army base in rural Britain, where they're subjected to cruel experiments by Dr. Caroline Caldwell (Glenn Close). School teacher Helen Justineau (Gemma Arterton) grows...