Filming locations were in Manchester, Liverpool and Cheshire, UK.
The exterior hospital scenes are actually Siemens offices in Withington, Manchester.
The series is set in and around Manchester. The gated community is in fact in Alderley Edge in Cheshire although after referencing the missing daughter as going south to the city, when they do arrive at the train station it's Piccadilly Station in Manchester which is north of Alderley Edge.