Doctor Who: "Knock Knock" Review

“Knock Knock” continues the feeling of Doctor Who’s current run trying out ideas that have long since been the show’s bread and butter by giving us a horror story set in a haunted house. TL;DR: It’s genuinely excellent up until the final three minutes, when the episode makes its only misstep… but unfortunately it’s such a large one that it does ruin things for me quite a lot.

A few alarm bells were set by the pre-titles sequence. Firstly, it revisits the idea established in the second half of Series 6 that the Doctor’s companions don’t travel full-time, but go home between trips. As previously discussed, I think this is a really bad idea and I really dislike that the show is still using it over five years later, but within the context of this episode it does actually go quite well. The haunted house in question, the one which Bill and her mates move into, is introduced by a landlord offering them a suspiciously cheap price, which is such a cliché that it’s another alarm bell, but fortunately the fear generated by this settles down once we get into the story.

One thing I don’t think I’ve made quite enough of in my reviews of this series is just how good I think Peter Capaldi and Pearl Mackie are. This is unquestionably the best Doctor/companion pairing of Moffat’s, and Bill is so much better a character than Amy, Clara or indeed River Song. And this week they’re accompanied by an excellent guest cast – David Suchet as the Landlord is an obvious standout (and Suchet’s confrontations with the Doctor are wonderful), and all of Clara’s flatmates, despite their brief screentime, feel like real people and are all nicely played. Characterisation of guest characters has been one of my two big issues with the Moffat era, and that isn’t a problem here at all.

The actual ghost story is good – it hits a lot of familiar beats for a horror story early on (guy messing about and pretending the house is haunted abruptly gets killed, things going bump in the night, etc), but it has a terrific payoff with a wonderful twist in the tale. Things could go badly wrong when the monster turns out to be some CGI insects, but the episode sells them well, with some rather arresting visual images. But then, right after the aforementioned twist, things go wrong with the resurrection of all of Bill’s mates, who in true horror film style have been offed one by one throughout the episode. The other big problem I have with Moffat’s era is its squeamishness and reluctance to actually kill anyone off and make it stick, and on this the episode falls down bad. The sudden restoration of everyone who’s been killed off makes for rather a big plot hole if you think about it, and it happens so late on and adds nothing. It’s a fairly baffling decision, and it is the only place the episode really falls down for me. I’m trying not to let it ruin the episode for me, but it does at least undo some of it.

Overall, though, this is a very good episode that just happens to make one misstep. A traditional horror story with a quite ingenious idea behind it. It’s frustrating, because this has just about everything that makes great Doctor Who for me, and one thing that really, really doesn’t and I can’t see why it’s there at all.