"The Version You've Never Seen" edition of the iconic demonic possession flick has a load of added material that, well, audiences had never seen, but there's an Easter egg in there that's even more tantalising. Keep the film running after listening to the second commentary by writer William Peter Blatty, and you'll hear Willian Friedkin introduce the tests of the film's terrifying demonic sound effects. As if one Captain Howdy wasn't enough...