Note: Doctor Who TV’s pre-air reviews aim to be as detail-free as we reasonably can while still offering a critique, but as everyone’s spoiler sensibilities are different, we advise you read on at your own discretion.

A group of young students are struggling to find a place to live. They’ve about given up when they encounter a creepy old man who just happens to appear in their hour of need. He offers them the perfect place, and it’s cheap to boot. Of course they accept his offer and promptly move in. What could go wrong? Unfortunately, something else is living in the house and it’s about to welcome its new guests.

If this all sounds rather like your typical teen supernatural set-up, then you’d be thinking along the right lines. Knock Knock, scripted by new to Who writer Mike Bartlett, basically plays out like a 45-minute horror film, with some Doctor Who trimmings naturally. The episode knows exactly what it wants to be and if you’re a fan of the things it’s aping, then you’ll enjoy this one a lot.

Following such a familiar template means you do fall into some of the trappings of the horror genre however. For instance, young people still make incredibly silly decisions and find themselves in harm’s way. And this sometimes includes Bill. While she has been shown to be sci-fi savvy, she could probably do with branching out a bit. Fortunately the Doctor knows a suspicious set-up when he sees one.

Knock Knock is also far creepier early on, when you aren’t quite sure of what’s going on and your mind is left to wonder. As the veil lifts and the truth of what’s really going on is revealed, the fear factor is lessened somewhat (2013’s “Hide” suffered a similar problem).

The first three episodes of Series 10 have been slower-paced character studies with a key focus on Bill and the Doctor, so it’s refreshing at this point to have an episode that feels more like a good old-fashioned, “spooky house 101” adventure. This does mean that the TARDIS duo’s dynamic is not quite as prominent though. For larger parts of the story the pair are separated. There are still some great moments, especially when Bill pretends the Doctor is someone else, with hilarious results.

It’s certainly nice to have a villain with a much bigger presence this week, something lacking in Series 10 thus far. Veteran actor David Suchet, of Poirot fame, brings to life the sinister Landlord, chewing on the scenery like his crustacean counterparts. Watching him and Capaldi verbally spar is a highlight. Even if latter developments make things clear it’s a case of more bark than bite.

Aside from the creepy crawlies, the main monster itself has a backstory that makes things more difficult to talk about in the confines of a review like this. But suffice to say Mariah Gale plays “it” in such a way that will have you questioning who is the real monster of the story.

There’s a fairly large cast of other supporting characters, but in true horror form, most are really only there for the bodycount. Mandeep Dhillon is granted a little more to do as Bill’s fellow housemate Shireen, while Colin Ryan’s Harry (a character with a link to the past) joins the Doctor for an unlikely pairing. And as for Nardole, he is not really worth mentioning again. He’s just there for what’s starting to feel like “Matt Lucas Cameo of the Week”. Better luck next week!

Director Bill Anderson (“Thin Ice”) brings a nice subdued build-up to proceedings, evoking a suitably unsettling atmosphere. Murray Gold adds to the vibe with a more haunting soundtrack. Wearing headphones is recommended.

Overall, Knock Knock is a decent, spooky throwback. It may not add a whole lot new, and the scares suffer a bit from latter revelations, but it’s an entertaining ride nonetheless.