David Slade knew that for the story to work, the predatory robot had to be a realistic threat for both audience and prey. The effective other half of a horror two-hander, the faceless, nameless robot had to convey all the dread of future where all forms of life were under attack. “We very quickly came to the idea in the backstory of what the robot was and how it’s made, that it would probably be a piece of military hardware. That it wouldn’t have generalized artificial intelligence, but it would have enough artificial intelligence to problem solve and that it...