Day 109: The Return

But another aspect of why the last episode's cliffhanger is so important and mindblowing is the way that it deals with cause and effect. Doctor Who is generally consisting of standalone episodes, where one plot has little to no impact on the next, save for a handful of mentions of previous adventures and stories featuring either the Daleks or The Meddling Monk. But even then, it is not direct effect that we are concerned with, only mild repurcussions from previous stories, but here the effect is far greater and more visible. It is entirely through the Doctor and co.'s influence that the events of this story have led to the conclusion. It is thanks to Dodo's cold that the humans suffered an illness from which they lost much of their willpower, allowing the Monoids to take over. We've come a long way from not being able to change history, as here the time travellers have actively changes the future. But this comes back to the constant quandary, of how much the Doctor's place in events shape the course of history, because if he's accidentally started a revolution with a cold, then what other changes through history have been created by the intrepid TARDIS crew?