Ah, Bad Wolf. Those elusive two words haunted the Ninth Doctor and Rose Tyler during their travels in Series 1 and it's been a pretty dominant theme in NuWho in general ever since. There was a time, though, that neither the Doctor nor the viewers knew what the hell it meant but all of our questions were finally answered in the Series 1 finale when it transpired that Rose had planted the words throughout time and space as a message to lead herself to the Doctor. Despite the fact the words were quite literally popping up all over the show, it took our heroes a pretty long time to work out that they held a particular significance to their lives. In fact, the penny didn't drop until episode 11, Boom Town, in which the titular Time Lord finally cottoned on to the fact that the phrase had been following them since day one. At this point you've probably noticed and overly analysed all of the references but, just in case you haven't, here's a rundown of all the most notable appearances, some of which are easier to spot than others. The phrase was first uttered during The End of the World when the Moxx of Balhoon can just about be heard mentioning the 'Bad Wolf scenario' in a conversation with the Face of Boe. The second reference came in the next episode, The Unquiet Dead, when the aforementioned Gwyneth reads Rose Tyler's mind and is frightened by what she sees, most notably 'the big bad wolf'. Then, in Aliens of London/World War Three, a boy spray paints the phrase on the TARDIS (graffiti it again and the Doctor will 'av ya!) and, in Dalek, Henry van Statten's private helicopter is called 'Bad Wolf One'. Coincidence? In addition, one of the channels broadcasting from Satellite Five in The Long Game is called BADWOLFTV, while, in Father's Day, a poster on the wall has had the foreboding words graffitied on it. The bomb Captain Jack rides in The Doctor Dances has 'SCHLECHTER WOLF' written on its side, and, in Boom Town, the Doctor, Rose and Jack arrive in Cardiff to discover a new project known as Blaidd Drwg. In short, they couldn't move for Bad Wolf references so It's a wonder it took them so long to put all the pieces together. The pay off was more than worth it, though, and it stands as one of the most intriguing and brilliantly executed story arcs in Doctor Who history.
Dan Butler is the Doctor Who Editor at WhatCulture.com. When he isn't writing his own articles or editing other people's, he can be found trawling the internet for gifs of Steven Moffat laughing. Contact him via dan.butler@whatculture.co.uk.