Wow, that was quite something.
Okay, so that's the episode in a sentence review out of the way, now lets get into the more detailed stuff shall we.
Lets start off with the plot premise here, and I would advise not reading any further if you haven't seen the episode yet, because I am going to spoil pretty much all of it. So, we kick off with The Doctor taking Clara and Courtney on a trip to the moon in the future because the Doctor hurt Courtney's feelings in the last episode. Of course, we know how good the Doctor is at keeping children under Clara's care out of trouble (see last seasons "Nightmare In Silver"), so as you'd expect everything goes tits up the moment they arrive and they find themselves on a crashing space shuttle in a room full of nuclear bombs. Ok, pause. I know the space shuttle isn't designed to land on the moon, but you'd have thought that NASA would have had a better plan than "oh, just let it crash", unless of course something went wrong, forcing the shuttle to crash, but they don't go into that at all. Meanwhile, in this very tame crash, none of the bombs manage to dislodge themselves from their rather frail looking holdings and blow everyone up, which is nice. Our heroes are then discovered by the crew of the ship, who threaten to kill the TARDIS crew, despite not having any weapons of any kind apart from aforementioned nuclear bombs and our heroes are only saved from this painful and agonising non-death by the Doctor talking an awful lot, which does of course give Peter Capaldi an opportunity to be smart, do a funny walk and play with a yo-yo. The TARDIS crew then join up with the three members of the shuttle crew to investigate a missing moon mission from Mexico (say that three times fast) which was apparently up there collecting mineral samples and has been missing for a year. We discover their moon base in fairly good condition, minus the fact the airlock has been blown open and the insides covered in what seems like spider web (plus the obligatory dead body, which has been devoured whilst still in its spacesuit, which is very Vasta Narada). This gives the team an opportunity to leave the token useless, over passive guy out side to do nothing until he gets eaten by the monster, which then proceeds to walk in the open airlock and into the moon base. Meanwhile our heroes are in the moon base discovering that they can get the oxygen working enough so that they can take their helmets off, despite the fact the airlock is open for the monster to get in and then set about finding out that the Mexicans found that the moon has no mineral trace (thus throwing all of NASA's Apollo mission data into disrepute and meaning that those 6 hugely expensive expeditions were nothing more than an excuse to drive around and play golf on an extraterrestrial body, but we'll ignore that for the sake of the story). All of a sudden the monster arrives, turns out to have the same weakness as the T-Rex from Jurassic Park (i.e. it can't see you if you don't move) and promptly kills one of the astronauts, leaving just one, the captain, who is cut straight from the same mould as that woman from "The Waters On Mars", being all over tough and "I must do my job, even though I'm really not sure what I'm dealing with and if that means I have to die then I will die and be happy about it. Hang on what do you mean I don't get to die, I wanted to die." (You know, basically summing up her entire character development in two sentences. And I think I did a pretty decent job). Then, after killing said extraneous astronaut, the monster turns on Courtney, who sprays it with anti-bactireal spray she just happens to have in her space suit pocket (no idea? Oh and also, where did the Doctor get those two extra spacesuits from any way? He nicked his from the base in "The Satan Pit"). The Doctor then surmises that the monsters that everyone at home thinks are spiders are in fact MASSIVE (yes, full capitals) bacteria (even though a bacteriological life form would not be able to grow to that size due to it's body structure, but hell what do I know. And here's a question for you. If they weren't spiders, what was with the webs?). Courtney declares she's scared and is sent back to the TARDIS, whilst the Doctor goes off to get attacked by aforementioned Spiderteria and then jump in a crater filled with amniotic fluid, which he emerges from a few minutes later quite dry. We are then shown a natty hologram of something inside the moon, which is apparently a giant egg and told that it is hatching. Clara of course expects the Doctor to make all the decisions and is quite dismayed (to put it lightly) when he summons Courtney back from the TARDIS and summarily buggers of to leave the humans to deal with it (much like Matt Smith did in the last Silurian episode, only he was much nicer about the whole thing). Clara then makes a broadcast to Earth to try to dump the burden on anyone else and humanity replies back in the only way humanity knows "kill it" (despite the fact that blowing up the moon would probably screw the Earth up just as much as the moon hatching into a giant space creature, but hey, we get to kill something). So of course they don't kill it, thanks to a very last minute intervention by Clara. The Doctor comes back, the egg hatches, doesn't destroy the Earth and conveniently leaves another moon in its place (and rather amusingly the tide still seems to be normal during the time the egg was being laid, which is highly unlikely). And finally it's back to school time for Courtney, leaving Clara alone with the Doctor, who she gives a very tart dressing down before declaring that she never wants to see him again and storms off. At which point the current best character, Danny Pink, comes in, makes some mysterious allusions to his past and makes Clara realise she does in fact want to see the Doctor again, and we end on some thought provoking shots of Clara looking at the moon. The End.
So, this episode has more holes in it than the moon would if it were made from cheese. The whole scenario the Doctor leaves the three humans with is a complete lose- lose, they blow up the moon- the Earth is screwed, they don't blow up the moon- the Earth is screwed 'cause the moon still gets destroyed. The lead astronaut was stupendously annoying once the Doctor returns to the scene, acting like she just went to the moon so she could kill herself. God almightily cheer up woman. And of course the premise its self is ridiculous. Bacteria that size would collapse in on themselves before they could even move a millimetre. But you know what. None of that even matters. Because this episode was truly and honestly fantastic. Five out of five. A+. And you know why. Peter Capaldi.
By rights this episode should have been a catastrophe. I've outlined all of its plot problems above. But I only really thought of those afterwards, whilst I was writing this. Because all the time Capadli was on the screen he owned it. I love the fact that he was just doing what we've seen the Doctor do before, but in his own gruff and awkward way. And the fact that he's still so new makes it better in a way. Of course we all know he's going to come back in the end, but apparently Clara still doesn't trust him enough yet and it makes the scenario work. And the fact he can't come back from Clara's rant at him at the end. He was not in the wrong. Not in any way shape or form. He's right, there are times when you have to make your own decisions, take responsibility for your actions and not rely on someone else. But he did it in such a brutal fashion (he basically said "well I'm out of here. Bye guys, oh and make sure you make the right decision, because either way it could cost lives. Not saying what the right decision is, but I'm sure you'll figure it out. Cheerio"), Clara had every right to hate his guts. It just worked so well it actually didn't matter how stupid the rest of the story was with all its plot holes and random inconsistencies.
Not saying that there still aren't problems though. And apart from the ones already listed, there's still a massive white elephant, which has been sitting there in the middle of the room, taking up room on the couch, ever since this series started. Clara. This was a character development episode for Clara, blatantly by how the story turned out. So why is she still leaving me feeling cold. Whilst she was mad at the Doctor I couldn't sympathise with her, all I could think was "yeah I see your point, but I can't really bring myself to care that much." I have no idea what it is still, but I honestly don't feel anything towards her. I don't like her, I don't hate her, she's just there, taking up space on the screen and to be brutally honest, if she had left the Doctor after todays episode, I wouldn't miss her. I wouldn't even care that she'd gone. And after 12 episodes and two specials as main companion (basically a full series), that's not a good position to be in. She's in the same boat as Martha, but Martha gets bonus points for following Rose, who is easily my least favourite companion by a mile. Clara has to follow Amy, who was peppy, inquisitive and feisty, plus she was a more interesting character anyway. I don't know if Clara is salvageable as a character at this point. I hope she is, but after having so long to make an impression and not having done so…..
So to round up: an episode that should have been terrible, given all the plot holes, that turned out to be good because the new Doctor is harsh and Clara doesn't trust him. Not bad.