Have I mentioned how I really love the fact that this season they've tweaked the opening theme to restore the 1970s intro to the theme? It adds an awful lot to what was, to me, a fairly ordinary version of the piece. And maybe, after a season, it's starting to grow on me so I don't find it quite as irksome as I did last year. Either way, the prelude that ended with that wonderful howl was just that little bit fantastic, all told. And, on top of that, Toby Whithouse's episode delivers one of the funniest gags the series has ever delivered (ie the Doctor requiring cards to be appropriate in certain situations). Now that the Doctor isn't quite as vitrolic as he was last season, his brusqueness is working for the character, and the new, lighter Clara, works fantastically opposite this Doctor, moreso, I think, than she did off his predecessor. As Sarah Jane was more a fourth companion than a third, so Clara is more a twelfth than an eleventh.
It's a fitting comparison for this episode, which was rather more interested in returning to the series roots than the new version of the series has ever been. Capaldi was doing a combination of Pertwee and Tom Baker, with his own twist on the part (indeed, in his black hoodie and trousers, you can't help but wonder if this is how Colin Baker would have played the part had he been given a free hand), while Toby Whithouse was writing as though Robert Holmes himself were script editing his work. This seemed like a Doctor Who story that could have quite neatly stepped out of 1975, as it flooded parts of Scotland and delivered us genuine ghosts - which weren't, but they were, but they weren't. And of course, the cliffhanger. The return of the Doctor Who cliffhanger can't be praised enough, and as Peter Capaldi stood in underwater mouthing "the dark, the sword, the forsaken, the temple", we got one of the best ever - along with a very iconic image.
Which brings us rather neatly to Daniel O'Hara, the director of this story. O'Hara is making his Who debut here, and limited by the number of effects shots he was clearly allowed to have, O'Hara makes the most of the underwater base he has been given, framing scenes to enhance the claustrophobia and giving us some stunning moments, including the cliffhanger mentioned, but also the rather lovely shot of the Doctor and Clara looking across at each other from across a flooded tunnel. O'Hara concentrates on faces, meaning we get to see the reactions from the cast before we generally get to see what it is they reacting too, which works very well in the case of the cliffhanger, and also the annoying Robert Pritchard's death. The other consequence of this is that this is definitely a character piece more than an action adventure. And rather helpfully, the characters are people we are genuinely interested in.
Casting on this episode includes some interesting choices. Colin McFarlane (who was Commissioner Loeb in The Dark Knight, Batman fans!) is killed off surprisingly early, but becomes the villain of the piece from that moment onwards; wandering around in black and white, muttering and killing and generally being very scary. The rest of the cast is extremely likable, particularly Morven Christie as O'Donnell, one of the many fans of the Doctor, it seems, who is delighted to get his approval and frankly would be a great companion if Clara doesn't make it through this episode (and will she? Who know, people, who knows...). However, let's not avoid the other rather astounding piece of casting - Sophie Stone. Stone is an actually deaf actor, and Doctor Who has cast a deaf actor before (waaay back in 1979), this is the first time the actor is playing a deaf character as well. I have no idea where this came from - whether it was in Whithouse's script (which would seem to be the case as, frankly, Lunn was relatively important to the story), or whether the decision was taken later. Either way, I fully applaud the decision as it gave us a character who was genuinely different to the norm. That said, I would have preferred it if the Doctor actually could read sign language...I mean...why wouldn't he? Regardless of the joke, by the way.
Ultimately, however, this was top notch Doctor Who. A fantastic mystery, a fantastic cliffhanger, fantastic direction, set design, writing, acting, characters...just all round brilliant. Bring on the next episode.