Multi-episode arcs are fairly commonplace on Doctor Who. During his tenure, Steven Moffat has implemented them a number of times, and, not too long ago, had an entire season made up of several smaller, multi-episode arcs. The results were mixed, to say the least. The Doctor’s adventures certainly seemed more expansive on the surface, but when you looked at each arc as a whole, the result was a longer single story, not necessarily a better one. The shift back to episodic story lines, then, has afforded the series a chance to play around with its tried and true Moffatian storytelling techniques, while also ensuring that the Doctor, his companion, and the audience see much more of time and space, thanks to single-serving stories.