While many things have changed in Doctor Who over the course of its 50+ year run, to include the main actors, companions, set locations and more, one thing that, until Series 7, had remained constant, was stories that were told over multiple episodes. Classic Who used them nearly exclusively, as each story arc would last anywhere from four to 10+ episodes in length. Series 7 was the only season in Doctor Who history in which each story started and concluded within the same episode. This isn't to say there were no overriding tory arcs (such as the First Question, why Clara lived in different timelines, etc), but many of the stories that were told could have benefitted from being made into a two-parter at least, if not more. Thankfully, Series 8 reintroduced the multi-part stories and, if rumours are to be held true, Series 9 will not only have many more, but will also open its season with a two-part story, too. Only a few short (long) months to go!