The Doctor Who episode Knock Knock was essentially a haunted house story set in normal, present-day London, proving that you don’t need to travel through time and space to have adventures with alien creatures. As Nardole cheerfully puts it at the end of the episode, “There are plenty of things that want to kill you right here!”

Originally I wasn’t the biggest Nardole fan, but I have to admit, he’s growing on me.

Spoilers after the break!

Even though she goes on adventures with The Doctor now, Bill is still a broke student. Now that she’s back in the present day, she’s moving out of her foster mom’s house. We are very quickly introduced to Bill’s 5 new housemates, and their flat-hunt begins.

Apartment hunting can be a nightmare in the best of scenarios, and the group’s search goes about as well as you’d expect when you have 6 people who can’t really afford anything. It seems like they’ve caught a lucky break though when they are met outside of the estate agent’s office by a very creepy man who happens to be renting a massive house.

source: bbc

That night one of the students, Pavel, moves in early. As he is setting up his audio equipment, he dismisses some creaking sounds as just the old house being an old house. However, as soon as the camera moves into the hallway, we hear him scream bloody murder. 

The next morning, The Doctor is helping Bill with the move, materializing the TARDIS around her things. I thought that this was adorable, and it was heartbreaking to hear his comments inquiring why she had so few possessions. (At this point I don’t think anything could make me have one negative thought about Bill.) While en route, The Doctor tells Bill that he is a Time Lord. It’s fascinating to watch him slowly reveal more and more about himself to Bill. There are clearly some very carefully placed lines surrounding their relationship, such as the specifics behind regenerating, that are slowly being crossed one by one.

source: bbc

Upon arriving at the house, The Doctor is immediately suspicious, and to Bill’s dismay insists on “helping” her get set up. Pretending that he is her grandfather, the two chat with the other housemates and we all learn some important things:

  1. They are not to go into the tower on the property, and no one can find the door to it.
  2. No one has seen the first roommate, but it is apparently normal for him to shut himself in his room and play music for days on end.
  3. This house is OLD. Old as in no central heating, no cell phone service, and the outlets do not support their electronics.

The landlord mysteriously appears and The Doctor immediately takes a disliking to him. After promising to address their concerns in the morning, briefly mentioning that he has a daughter who is “under his protection,” and performing a very neat trick with a tuning fork, the landlord mysteriously disappears again.

The group then does the one thing that you should never do in a haunted house: they split up. Bill, Paul, and Shireen go upstairs and The Doctor, Felicity, and Harry stay downstairs. Things very quickly take a horrifying turn and the wooden doors and shutters to the house begin sealing shut of their own accord. 

Bill and Shireen finally check on Pavel, and are horrified to discover that not only is he part of the wall, he is still alive but trapped in the wood! The landlord appears and reveals that the music loop from Pavel’s record player is keeping the process paused, and as he lifts the needle from the record, Pavel is completely consumed by the wood. Bill and Shireen flee to where they assume the entrance to the mysterious tower should be. Luckily their hunch is correct and they disappear behind a secret bookshelf door.

source: bbc

Downstairs The Doctor and Harry discover that the source of the noises in the house are alien bugs that The Doctor suspects are some sort of dryad or tree spirit. They flee to the basement where they discover the belongings and rental agreements of the previous tenants. It appears that every 20 years the house is leased to a new group of six. Judging by the Polaroids found in one of the boxes, the tenancy has not ended well for any of them.

The Landlord suddenly appears again and explains that his daughter was dying and the bugs saved her. As Harry is (horrifyingly) consumed by the bugs, The Doctor pleads with the landlord to let him see if there is something he can do to help his daughter.

Upstairs, Bill and Shireen quickly realize that they are in the daughter’s room. Introducing herself as Eliza, the mysterious woman appears from behind a screen; she is completely made out of wood. Shireen is the next to fall victim to the bugs, and as she disappears, Eliza glows with energy.

The Doctor and the landlord arrive, and The Doctor quickly theorizes that the landlord had brought his daughter some insects that he found and accidentally activated them by opening the music box on the table. Bill quickly points out that people don’t just show up with weird bugs. (Unless you’re The Doctor) and that if the landlord is really Eliza’s father, he should be dead.

source: bbc

Bill is very observant. It turns out that the landlord is, in fact, Eliza’s son, and the bugs do not preserve the memories of those that they preserve. Eliza is horrified and is determined to right her son’s wrong. She uses her connection with the bugs to stop their advances towards Bill and after her son refuses to leave her, she embraces him as the bugs consume them both. This moment was very intense and incredibly dark. However, we are barely given time to process that Eliza technically just committed a murder-suicide as almost immediately Bill’s flatmates are all pushed out of the floors and walls alive and unharmed. The house starts shaking, and everyone runs outside just in time to escape the entire building being demolished by the bugs.

Back at the vault, The Doctor gives Nardole the night off guard duty as piano music comes from behind the door. Clearly, The Doctor knows who or whatever is captive in the vault. In an incredibly frustrating cliffhanger: the episode ends as he opens the doors and does not reveal who he greets inside.

source: bbc

This episode was really all about Bill and how her relationship with The Doctor fits into her everyday life. She was very reluctant to have him help out with the move and seemed embarrassed of him at times (though to be fair, he is incredibly awkward and she was trying to make a good impression on her new flatmates). She went so far as to tell him “This is the bit of my life you’re not in”. Since past companions have not had the best track record of keeping a healthy Doctor-life balance (Clara especially had a difficult time keeping her two lives separate) I am anxious to see how Bill’s relationship with The Doctor develops.

Besides learning more about her relationship with The Doctor, we also got to learn more about Bill’s past thanks to little moments throughout the episode that showcased her personality. My personal favorite was when she held up her mom’s picture to show her her new room. This moment basically solidified my eternal love for Bill. A close second was when she was giving herself a pep talk saying that there was nothing to be scared of, just “a new house and people you don’t know” which, of course, is actually terrifying but also completely relatable. It is so refreshing how normal Bill is. After only four episodes, she already seems like a friend.