I remember being a bit nonplussed by this story on initial broadcast. I certainly didn't make the link between this and the previous special through Harmony Shoal, but then it had been 12 months. And overall, there was something about this episode which just left me a bit cold.

Rewatching stories often changes my general impression and often overall opinion of them. Unfortunately, The Return of Doctor Mysterio is not one of those occasions.

Peter Capaldi is great. Although he will always languish towards the bottom of my Doctor rankings, I have warmed to him more over the last couple of years and he is fun in this story. This is helped enormously by the return of Matt Lucas as Nardole. With a few vague references to his fate in Husbands, he's back in humanoid form and rocking the 'I'm just as clever as the Doctor' schtick that we've not really seen since Romana.

The scenes of him piloting the TARDIS having spent some time ruling in the Byzantine Empire are hilarious and it's clear the Doctor almost treats him, if not as an equal, certainly not in a way he usually treats his companions. It's not the same relationship he has with Clara or Bill.

I like the 'Doctor Who does a Superhero movie' concept but it's a shame they chose to basically do Superman. Superman is easily my least favourite superhero. Aside from Superman 3 (which has that bit with the woman being turned into a robot which terrified me as a child) most Superman films are boring as hell. My wife liked Smallville, although I could never get into it, and the only iteration of Superman I ever enjoyed was Dean Cain in Lois and Clark).

So, right from the off, this story is on to a losing streak with me. Unfortunately, the boring superhero concept is coupled with a dull performance from Justin Chatwin as Grant/the Ghost. He's just not very interesting as either Grant or the Ghost. The Ghost gets the traditional deep, rumbly voice ala Batman but Chatwin can't really pull it off.

The other main guest star is Charity Wakefield as Lucy - the Lois Lane substitute. She is better and more fun and I quite like the way she takes no nonsense from the Doctor. But, ultimately, she is just 'doing' Lois Lane - spunky reporter who, yet, is too stupid to realise her child's nanny is actually a superhero.

I do like the way that the Ghost comes to be and actually, the best parts of his story are when he's a child. I particularly liked the scene in high school where his powers are being influenced by his adolescent urges. I feel like there would have been a more interesting story to be told here, but maybe that would be better for an actual superhero movie rather than a Doctor Who riff on one.

The other huge problem with this story, for me, are the villains - Harmony Shoal. They are just so dull. I couldn't even begin to remember the names of the two guys they have taken over and the whole idea of living brains with eyes sitting in jars and then being transplanted into human hosts seems half-baked. Again, the split-head effect is, I feel, too gruesome for Who but ironically is also the only interesting thing about them.

There is quite a good scene where the Doctor confronts the leader and realises stuff about their plans, but all in all Harmony Shoal are one of Doctor Who's least effective and least memorable antagonists. And quite how or why this ties into their appearace in Husbands where they have a slightly different name and a completely different modus operandi is never adequately explained, explored or frankly, even mentioned.

I've said before that, for me, the worst Doctor Who stories are those which are dull. A story can be 'bad' but I may well still enjoy it on some level: a Time-Flight, a Timelash or a Time Monster for example. But if a story is just boring, that's more of an issue. There have been a few stories in the modern series that have bored me on first watch - The Rings of Akhaten, In the Forest of the Night for example, but they deserve a revisit and chance of re-evaluation. Doctor Mysterious has now had that re-evaluation and it's still found wanting. The story is dull, the superhero concept is the dullest they could have chosen (and I love superhero movies in general), the villains are dull and the central guest character is dull. It all looks quite slick and glossy but, at the same time, even the locations and sets have a dullness about them.

I originally said that I wanted to rewatch Husbands alongside this story this time round to look at them as a pair, what with the Harmony Shoal link. All it's done is highlight the contrast between a fun, vibrant, sparkly Christmas special and a dull, sombre, uninspiring one.

A fun parody of superhero movies, I couldn't say that there's much to discuss about this one, but that's OK, I'd say. It's easy to just have fun with, Harmony Shoal serve to have some good, creepy moments - even if that possession of the UNIT soldier went nowhere.

It is what it is.