Let me review the new Sherlock episode in a non-spoilery way:
It was good!

Right, now that's out of the way, let's go into a little more detail. WARNING: SPOILERS UNDER THE CUT.

This episode did not disappoint! Watching the first episode of the second series is very different from watching the first episode of the first series, but I think that's unavoidable. This episode is a different kettle of fish from A Study in Pink but I enjoyed it a great deal nonetheless!

Here's the part where I apologise if I don't make too much sense in this post. I've been wired since about 10am yesterday morning (and I had some feverish dreams about bees last night. No, seriously) so this post has gotten a little long-winded. Oh dear.

Let me bullet point things a little to make it marginally less chaotic.

Contents:
1. Gosh, that was quite sexy?
2. Let's talk about Sherlock and Irene
3. Sherlock and John
4. Sherlock and Mrs Hudson
5. Sherlock and Molly
6. Sherlock and Mycroft
7. The actual plot
8. The direction
9. The costume design
10. The silliness
11. Conclusions

***

1. Gosh, that was quite sexy?

Sexy or sensual? I'm not sure. But whatever it was, this episode had it in spades. The air practically crackled with tension. Not only that, we had random nudity, a lot of physical violence, extremely intense silences, a glut of smoking, plenty of violin playing, cheekbone references and a dog collar. Not to mention Sherlock taking Irene's pulse. I nearly swooned.

Ahaha, and all through the tension, John tries manfully to not be distracted by the surprise bondage lesbians. Good luck, John.

2. Let's talk about Sherlock and Irene

I have to say, I was worried about how this episode would turn out. The first series did a fantastic job of leaving Sherlock's romantic preferences (if any) rather vague. We're told that Sherlock does have a heart, even if he believes he doesn't, but that's about it. The upshot is that it's all a little complicated but ultimately Sherlock gives it very little thought and whatever it is, 'it's all fine'.

I was concerned that this delicate characterisation would get bludgeoned aside by the introduction of Irene as a love interest. In Caitlin Moran's wonderful article about the show, Moffat and Gatiss talk about how they sat down after the first series and had to work out if Sherlock was gay or not. This led me to the worrying conclusion that Sherlock's sexuality would thus be set down in stone in A Scandal in Belgravia and that, apparently, in TV-land we're still living in a world where a person is either gay or straight and nothing else. Add to this the promo pictures of bedsheets and naked-Irene and I was almost convinced we were going to get Sherlock falling in love and jumping into bed and generally mooning around not being very Sherlock-like at all.

Thankfully, my worrying was for nothing. This episode, and Sherlock's relationship with Irene, was handled superbly. There were no definitive proclamations of 'Sherlock is gay' or 'Sherlock is straight' and there was certainly no romance in the normal sense of the word. Throughout it all, Sherlock remained Sherlock: more interested in puzzles than anything else and perhaps even more ambiguous than before.

That's not to say that there was nothing between Sherlock and Irene. There was certainly something, but that something is very hard to define. You get the sense that they're both intrigued and impressed by each other, and there's a lot of one-upmanship going on. There's an obsessive sort of fascination for the both of them, and it would be very similar to Sherlock's flirty relationship with Moriarty were it not for the fact that a) Irene is not criminally insane and b) Irene is overtly sexual in her advances.

So, is it sexual tension that's going on here? There's no way of knowing for sure; it's played so very cleverly and that's what I adore about it.

Irene identifies as gay but propositions Sherlock for sex multiple times. It's hard to tell if she is sexually attracted to him or not; after all, sex is her stock in trade, so maybe she's just employing what she knows to push his buttons. Then again, Sherlock's observations suggest that Irene is aroused in his presence, but whether that arousal is lust, love, admiration, or the thrill of the game, it's impossible to tell.

Sherlock, we see, is flustered by Irene. I doubt it's the first time anyone's come-on to him, but if anyone else called him sexy, would he really get so tongue-tied? He never accepts any of her sexual advances, but he doesn't dismiss them either. This creates some epic silences, and every time, it looks as if Sherlock's on the verge of saying yes. Is he sexually-attracted to her, or is he just intrigued to find out what she would do next?

For me, though, I think the most elucidating part is when Irene asks Sherlock to """"dinner"""" (in massive inverted commas here, nudge nudge wink wink say no more say no more). And Sherlock replies, "Why would I want to have dinner if I wasn't hungry?"

I think there, we get an answer. Sherlock (at least, this version of Sherlock) appears to be asexual rather than sexual and celibate. Apparently, he just doesn't get hungry. However, the tension in that scene is such that you have to wonder; is he slightly demisexual for Irene? Or is he even lying for his own purposes, whatever they may be?

Personally, I like the view of asexual!Sherlock and Irene being a little more bisexual than she'd originally thought, but at the end of the day it doesn't matter. What's important is that unlike my fears, this episode is all sorts of ambiguous and enthralling because of it. Sherlock was Sherlock and was never out of character in the slightest.

So, was it love? For my part, I don't think that it was. There was attraction, certainly, and fascination and obsession, but I wouldn't say love (not without more time, at least). And this becomes more clear when you compare Sherlock's relationship with Irene to the other relationships in Sherlock's life (the comparisons aren't hard to make either; they are set out in the show, but in a way that's subtle enough to be enjoyable).

3. Sherlock and John

This episode was very insistent in saying that Sherlock and John are a couple. In the first series, the same thing was said, but in a much more jocular 'oh ho ho everyone thinks they're gay for each other, isn't that funny' sort of a way. But in this episode, it wasn't played for laughs, it was just there.

Obviously, Sherlock and John aren't a couple in the most common sense of the word. They're not boyfriend and boyfriend in a monogamous relationship, going on dates and being physically intimate. There won't be wedding bells and the patter of little feet in the air. But, they are important to each other. Now that they've found each other, the idea of Sherlock without John and John without Sherlock is almost inconceivable.

From this episode, and the previous series, it is so very clear that Sherlock and John love each other. They bicker and they fight but John cares about Sherlock and would do anything for him; and despite Sherlock's prickly personality, we know that Sherlock would do the same.

I doubt their love is sexual. I'm sure John would say something if it was, but he declares (many times) that he's not gay, so we must take him at his word. I've already discussed Sherlock's sexuality at length, and he hasn't done anything to suggest that he's attracted to John in that way. So be it.

Not sexual but still love, then. Whether it's platonic or romantic remains to be seen. I can't really see Sherlock doing romance, but their friendship seems so strong that platonic doesn't quite cover it. Personally, I like to think they inhabit the fuzzy area that sits between the platonic and the romantic, but that's a discussion for another day.

John's relationship with Sherlock is mirrored with Irene's in a very nice way during the scene in Battersea Power Station.

John says: We're not a couple.
Irene says: Yes you are.
[...]
John says: I'm not actually gay.
Irene says: Well, I am.
Then, Irene says: Look at us both.

Neither of them should be attracted to Sherlock, but they've both fallen into his orbit nonetheless.

It seems as if both John and Irene want to push Sherlock onto each other. John might think Irene's a bit crazy, but he honestly tries to get her and Sherlock to make a go of it because he wants Sherlock to be happy. John, you are utterly precious. Irene, it seems to me, realises that John is just as entangled with Sherlock as she is, but John doesn't quite get it when she tells him. And then they both get a little jealous of each other without realising it. I'll say it again: precious.

4. Sherlock and Mrs Hudson

I adore the way this relationship was developed in this episode. Sherlock can claim not to care about anything until the cows come home, but it's clear that he cares about Mrs Hudson a great deal.

It's a very mother/son sort of deal. Sherlock grouches at Mrs Hudson and Mrs Hudson complains about having to pick up after Sherlock but they are still very close.

Sherlock shouting at Mycroft for insulting Mrs Hudson was wonderful. And, well, when Sherlock attacked the agent who'd beaten up Mrs Hudson, it was a little scary. We've never seen Sherlock be so wilfully dangerous before. Beware anyone who goes after those that Sherlock cares about. (And when Sherlock hugs her afterwards 'England would fall' I nearly teared up.)

5. Sherlock and Molly

Poor Molly. Sherlock is casually dismissive and downright cruel. The comparison between Molly and Irene is clearly shown when Sherlock dismisses Molly's Christmas present but jumps at the chance to open Irene's. Molly might be a nice girl, but she doesn't hold Sherlock's attention like Irene does.

That said, there are plenty of people that Sherlock doesn't care about at all, and Molly is not one of them. Sherlock might be dismissive of Molly, but he tolerates her; and he may be cruel but most of it is unintentional. I seriously doubt Sherlock would apologise to just anyone.

So, no, it's not love (on Sherlock's part. Sorry, Molly). But I like to think that he respects her, just a little bit.

(By the bye, let me add my name to the list of growing Molly/Lestrade shippers. It did seem that that was where the episode wanted to take us. As soon as they showed a little hint of Lestrade and Molly liking each other, there was suddenly a long discussion about Lestrade's marital status, or lack thereof. I see what you're doing, show, I see what you're doing. And I approve.)

6. Sherlock and Mycroft

We never see anything but contempt from Sherlock to Mycroft, but their bond hasn't yet been tested. I like to think that deep down, Sherlock has some affection for his brother somewhere.

Mycroft, on the other hand, clearly loves his brother a lot. It's not hard to imagine that, to Mycroft, Sherlock is still the inquisitive young boy who needs to be protected. Of course, being Mycroft, he does the protecting in an aloof and (very) creepy way.

Still, at the end, it's obvious that Mycroft doesn't want to hurt Sherlock with the news of Irene's death, and the smile he gives when he talks about Sherlock as a child is adorable.

As much as Mycroft councils Sherlock that it's not necessary to care about people, Mycroft proves himself wrong. Immediately after their conversation, Mycroft calls John to ensure that Sherlock will be safe that night. Oh, Mycroft.

7. The actual plot

But that's a lot of talk about characterisation. Wasn't there some plot in there somewhere?

Can I say, for a start, that the resolution of the cliffhanger was simultaneously anticlimactic and hilarious? (I say anticlimactic because there was no giant lizard or mariachi band. Internet, you lied to me.) I love the idea of Moriarty having the Bee Gees as his ring tone though. Please never stop being camp, Moriarty. Gosh, and his 'I will skin you' line was terrifying (and vaguely arousing, or was that just me?)

For the first 30 minutes, this episode felt like a sitcom (that's a compliment). It was gag gag gag and I loved every minute of it. Of course, the jokes subsided when the tension ramped up, but I loved that part too. Seriously, this show was far funnier than the episode of Absolutely Fabulous that followed it.

Oh, God, and the part where John walks into Buckingham Palace to find Sherlock in a bedsheet was hilarious. The extended silence was allowed to run and run and it was fantastic. The comic timing on this show is great, but I think a special mention needs to go out to Martin Freeman who, I am becoming convinced, is a superb comic actor.

The rest of the plot was a little confusing. I had to watch the episode twice to try to get around some of the twists and turns. I'm not complaining though! Straightforward would be boring. So, there was something to do with a plane and some stuff? I was concentrating on the sexual?-tension too hard to really pay attention.

8. The direction

Very nice, just like the first series. This episode was a little trippy though. I'm not sure how I feel about that. I normally like trippy, but felt like it was used a little too much here.

The whole show is beautiful though, and I won't hear otherwise.

9. The costume design

Let's not dwell too much on what it would be like to wear That Coat while naked. Ok. What I enjoy is how they manage to make 21st century outfits look so oldschool. Irene's hair, I'm talking about you. On my second rewatch, I think I spent most of my time wondering how to recreate that hairstyle.

And a big shout-out to Irene's outfit at Battersea Power Station. That jacket with those gloves was rather wonderful.

Of course, the biggest shout-out goes to John's Christmas jumper. As soon as I saw it, I thought: Oh, wow, so John likes to go in for the Sarah Lund cosplay too! Good man, John.

10. The silliness

There were some bits that didn't sit quite right though. Fortunately they were few and far between.

Firstly, the hat. It was funny, yes, but really? Really? Did you just go there? Because I think you just went there.

Secondly, SHERLOCKED. SHERLOCKED. Seriously, I am willing to suspend my disbelief so far. But not this far. Show, you are being ridiculous.

Thirdly, the 'beheading' at the end. Come on. This was a very silly end to a what had been a good episode. I don't know what irks me about it. It could be the fact that it seems far-fetched (hard to be too far-fetched with Sherlock Holmes though), or it could be the fact that it was trying to be too mysterious and exotic (this is the problem I had with The Blind Banker). Did Sherlock and Irene go for dinner in Pakistan afterwards? We shall never know.

11. Conclusions

Well, that was long-winded and oddly embarrassing. Let me some it up neatly:

There were some silly bits, yes, but on the whole this was a very well-executed show that was tremendous amounts of fun to watch. I say, bring on the hounds!

p.s. Take a look at John's blog. There's some new stuff on there and it's great. Jacob Sowersby is super and a little bit scary.