TV Orphan Black was my favourite new returning series of 2013, the BBC America/Three drama about the subjects of a cloning experiment attempting to deal with the who, what, when, where and how of their existence whilst dodging the police and shadowy organisation that made them. Created by John Fawcett and Graeme Manson, previous credited on the likes of Flash Forward and The Bridge, it's one of those series which doesn't seem to care at all about burning through story elements that other shows would have stretched out across a year and comedy at the expense of its own premise. Its killer app (if it's possible to describe a person that way) is Tatiana Maslany. There have been plenty of other examples of actors playing multiple characters, notably recently the Cylons in Battlestar Galactica, but the glory of Maslany's lead performance is that at a certain moment, some way into the second episode (aided in no small measure by the technical marvels outlined below and Kathryn Alexandre, her acting double), you forget that it isn't just one actress in all of these roles, the runaway, the soccer mom and the science student (and others) even when they're in the same room. For each character, not just her voice, but her physicality changes and as the series continues you realise that you're watching what's become a ensemble show in which half the cast is one actor. She's written a blog post about her process (and this spoilery video put out after the end of the first season) but it's probably not easily put into words. What she demonstrates is that some actors are chameleons.