Of the several parallel worlds created in the name of Doctor Who, Turn Left provides us with the most intriguing. What would the world be like without the Doctor? The answer, apparently, is a very, very grim place. Tricked into changing the past by a nasty fortune teller with a pesky time beetle to hand, Donna lives in an alternate Earth where the Doctor died during his Christmas encounter with the Racnoss (that originally happened in The Runaway Bride, fact fans). So without its guardian Time Lord to protect it, the Earth falls foul of every single alien invasion the Doctor had saved it from; the Titanic crashes into Buckingham Palace, the Adipose turn millions into fat, the Sontaran Stratagem to choke the world almost works (foiled by the self-sacrificing of the Torchwood team), etc. All of which leaves the Earth, particularly the UK you know the universe's obsession with attacking that neck of the woods an irradiated, over-populated mess. Until, a reality-hopping Rose Tyler is on hand to help... Apart from being one of the most fan-servicing episodes of its era ('oh, look its that episode again! Oh, and that one!'), Turn Left is a really effective and one of the most Earth-shattering takes on the alternate timeline idea. The advice to take from this, readers; always turn left at a junction.
