In 2013 an apparently simple, back-to-basics scary movie transformed horror cinema for the rest of the decade. Based on the allegedly true story of the Perron family haunting and subsequent investigation by ghost hunters Ed and Lorraine Warren, The Conjuring has to-date spawned six sequels and prequels, making up a Conjuring 'universe' that has taken over a billion dollars around the world. The New York Times called The...