Personally, this episode really wasn't the best. It was filled with fan service, had a slightly mediocre ending, and some plain lazy twists. However, the comedic element to the mystery of the case itself makes the episode enjoyable at least.In depth spoiler review here: https://www.youtube.com/watch?v=ZcUI55HnBqY

I love all the other Sherlock episodes, some more, some less, but this one is not one I will be watching again. It's silly, strained and trying way too hard. The weird make-up, the forced social message, none of it really worked at all. About the only part I liked about it somewhat was the retro look. The way they tried to explain things at the end was put together in a rather slipshod and really just silly, unsavoury manner. The story did not hold together very well at all. And it certainly did nothing to link it to Moriarty.Alas, it just wasn't at all enjoyable.

Can't say enough good things about this. Let's start with what it is not. It is not rewarding long form filmmaking. It is TeeVee, and despite the rush of talent into TeeVee series, and their ability to engage, this will never be the sort of thing that we go to for lucid dream walking. The techniques I will be lauding here have been used for decades in films that matter, let's say for example by Ruiz. But never in the mainstream like this.But this thrills me because it makes explicit folding the default for popular entertainment. Oh, it is masked by energy and OCD. And too much is 'explained' by way of drugs, mind palaces and so on. But this is mainstream, big time popular stuff and its primary structure is that of folding.We have a Victorian character set in modern times who is transported back to the referenced context. This is done by drugs, by an unrelated inner space of visualized 'working out.' We have the reality, two realities in fact conflated with the stories written in each reality, sometimes shifting control. We have the fold that Conan Doyle put in, the one about Mycroft and Holmes directing each other.And then there is the staging where reality and the account of reality are merged.And we get it. We like it. Ten years ago, we were still in Mary Tyler Moore territory. A mass audience wouldn't follow these shifts in abstraction, these skips among parallel realities and creating spaces. I wish it were not served as a device to keep the attention of dopes that can't pay attention. But it is sophisticated abstract reasoning nonetheless, and we didn't have that, even remotely when I was a kid.

Season 3 of this show already saw it confirmed as 'event television', and there is a greater feeling of that with this first episode to what IMDb calls 'season 4'; although it has been a year and a half since the last 'season' ended, and will reportedly be that again before we see another episode. I remember feeling that season 3 was a bit too pleased with itself for my tastes, and this is magnified here, where lots of increasingly famous and successful people are crowbarred into place to deliver this episode – and to be fair it must have taken a huge amount of schedule balancing to make it happen, so credit for that.I guess there was also the risk that this amount of effort, and the fact that the stars no longer really 'need' Sherlock as a vehicle, means that there is a feeling of them doing the viewer a favor. As part of this as well, it must be tough for the writers, as they are trying to write an ongoing story without knowing when/if they will get the next episode. There is a sense of both these things with this episode, which occur in the few minutes that the plane takes to turn around and land so that the banished Sherlock can deal with the apparent return of Moriarty. In the jump back in time, we enter Sherlock's mind as he tries to solve a similar mystery he read about. This jump back in time allows the writers to not have to worry too much about where/how to advance the Moriarty plot, while at the same time appearing to advance it. It also gives them a chance for a bit of fun away from the modern settings.And it is fun, in a way, although it is also heavy with flaws and weakness. The time-hopping doesn't help the actual mystery which is the focus of most of the time, nor does it really fit in the modern setting either. This sense of it not really working, and not really doing much for the viewer also means that, while it is funny and entertaining, it does feel like it is overly pleased with itself at the same time. That sense of indulgence and knowing it is a big deal does come through – not heavily perhaps, but I did find it hard to shake. It is all still an expensive and impressive production technically, but it is messy and the fun elements come almost by force of personality rather than wholly by design.Sherlock is such a hot property for the BBC, and with the effort it must take to even get one episode made, you can see why they are happy with whatever. However, with this so-so episode coming on top of the equally below-expectations season 3, it does make you wonder realistically what the plans are for this. Hopefully they can work it out for a decent handful of episodes to be completed as part of bringing the series to a close in a meaningful way rather than limping ahead like rock stars playing half-assed gigs in small venues so they can 'keep in touch with their roots'.