Director of The Babadook, Jennifer Kent explains how she used the psychological to create horror, and the talks about the challenges in casting kids. Film critic Kim Newman takes a look at children in horror films, from The Innocents to The Exorcist. British actor Riz Ahmed discusses his new role in Nightcrawler and discusses the role that instant internet news plays in todays media and our responsibility as consumers of it. Francine Stock presents a new series running throughout The Film Programme for the next two months- The Story Of The Sound Effect. To mark the BFI's season Days Of Fear And Wonder, the programme will hear from the people who created some of the most famous sound effects in the history of science fiction cinema. This week, Ben Burtt on the lightsaber.