Doctor Who – Knock Knock Review
"Knock on wood too long and the wood will knock on you"
"Knock Knock," the fourth episode of DW's tenth season, is the weakest episode so far, indulging in overused horror cliches and an undercooked plot at the expense of interesting characters.
Bill and five of her friends are looking for a house to share - one that they can actually afford, that is. A creepy landlord (David Suchet) offers them a suspiciously cheap deal on a big house that's old, creaky, and sinister looking, so naturally they go for it, no questions asked. When The Doctor stops by to help Bill move her stuff, he instantly realizes something's not quite right and decides to stick around.
Up to this point, the tenth season always compensated for any problems episodes might have with a strong character focus. "Knock Knock" unfortunately bucks that trend. Bill's housemates are thoroughly underwritten and uninteresting - they mainly seem to be there so that the monster of the week will someone to kill. One of the guys is interested in Bill and she eventually tells him she's a lesbian, which we already know, so nothing of any significance was accomplished by that whole subplot.
Worse still, The Doctor and Bill themselves get a bad dose of this. Like in previous episodes, The Doctor gives Bill a few more bits of key information, the big one being that he's a Time Lord, but the exchange is clunky and stilted. After that, their interactions boil down to Bill being embarrassed that The Doctor is around and trying to get him to leave. It touches upon the familiar idea of a companion trying to keep their Doctor-life away from their life-life, but it goes nowhere, especially when the two spend the majority of the episode away from each other.
Old creaky house, creepy old man, no cell phone signal, ominous lighting strikes, and dumb young people doing dumb things - "Knock Knock" is full of horror tropes, but doesn't really bring anything new to the table. There's a Doctor Who spin on it, in that the explanation is aliens, but apart from that, there's not much that really stands out. The episode tries to have some emotional weight to the monster, but it falls pretty flat, mostly because the big emotional scene is muddled in a giant exposition dump.
The most interesting part of the episode has absolutely nothing to do with the main plot. It is another bit of information about the mysterious Vault the Doctor is guarding - now we know that there's someone inside that The Doctor has a soft spot for, what with giving them a piano and bringing them food. The obvious answer is that Missy is inside, especially when the prisoner expresses delight at the prospect of young people dying - but this is Moffat we're talking about, so it could very well be a misdirection.
Overall, "Knock Knock" is the first big disappointment of the tenth season. It's just a lackluster, forgettable episode with next to no standout moments or interesting developments. Let's just hope it's a fluke and that the show will be bounce back next week.