Can a machine ever be truly intelligent? Can it have feelings? If a machine fakes these things convincingly enough, at what point does the appearance become the real thing? Whatever the answer, Hollywood tends to remind us that it’s a bad idea to fall for robots and AIs, however seductive they look and however much they sound like Scarlett Johansson. Ex Machina is not alone in dramatising the Turing Test, but Alex Garland’s first film as a director is definitely a striking addition to the genre.