Anyone who has watched Doctor Who, old or new, knows that the show's continuity is one of the most complicated in the world of sci-fi TV. Since the '60s, the canon established in Doctor Who's greatest episodes and classic era serials has created a wild and adventurous world for viewers to engage themselves in, even if it is a little confusing at times. When time travel is involved, anything is possible, and unlike most other sci-fi titles, Doctor Who's story allows for plot holes and continuity errors to be swept under the rug more easily.