One of the biggest challenges facing any science fiction or fantasy series is to get the balance between creating excellent adventures and encouraging long-term emotional investment. Ignore the latter and when you want to create a big hefty scene where a lead character dies or leaves you find yourself with an audience not that bothered and just wanting to you to move on to the next big showdown. Ignore the former, and you don’t really have a sci-fi/fantasy show at all, just a drama with a few weird references.

Doctor Who tackles this problem with varying degrees of success. In the Russel T. Davis era, it did this very well, bar the odd episode. The plots wrapped you in nicely and had a zing to them, but you still cared about the characters. One of the times I’ve cried at the TV was when the hologram of The Doctor cut out before he could say ‘I love you’ to Rose.

I feel, in my personal opinion, that the Steven Moffat era has been less successful. For a start, I have never fully understood why the loss of Clara Oswald is felt by The Doctor with the pain that Amy Pond or any others were not. So that’s the emotional investment side not hitting the right note. Then we have the adventure side, which I also feel is sometimes lacking. Too many episodes seem to end with The Doctor knowing what he was doing all along, which makes you wonder why someone so keen to save the world lets so many people get harmed in the process.

There are some bright moments though. I have always liked Peter Capaldi as The Doctor, playing him both that bit darker but also with stronger vein of humour than some of the other recent incarnations. I also think Matt Lucas as Nordole becoming a semi-regular character is a smart move, as I feel the Tardis actually needs a trinity of people. I’m undecided on Pearl Mackie as Bill – her mouthiness is welcomed but I feel we were spoilt in our early days with the near perfect Rose Tyler, with only Amy Pond so far coming close. I think the best solution is to give Bill time to grow.

Best of all though is we still have Michelle Gomez as Missy. Like Capaldi, she is bowing out this series, and could actually end up being the greater loss. There is a fizz from her that cannot be replicated. Her voice is an iron fist wrapped in a velvet glove. Like all the best villains, she makes being evil look fun.

There have been some genuinely strong individual episodes in this run. Thin Ice felt like a Tennant-era classic – evil human bad guy thwarted and some good done to the world in the process. Extremis has set up some interesting concepts and given us a decent story arc to get our teeth into. When the stars align, Doctor Who can still pull out a corker of an episode. But it needs to do this more often. The show is having a reboot next year – new Doctor, new showrunner. A perfect opportunity to audit it and gives us the best the show can be.