Headscratchers / Barbarian

• Who exactly was renting out the house on AirBnB and other apps? A.J. wasn't, and his property manager said they hadn't rented it to anyone in weeks (Tess and Keith haven't been missing long enough for anyone to notice, apparently). No one ever calls Tess back after she leaves a voicemail. Neither Frank nor the Mother appeared to have any computer literacy or even own a computer, so they probably weren't renting it.
  • Given the state of the surrounding area, the house could've been easily repossessed by a real estate company and then rented out. Though the tip-top shape of the house is rather questionable.
  • The house is AJ's. He bought it some indeterminate time ago as an investment and hired a property management company to rent it out to people. They're who Tess and Keith deal with when they rent it.
    • They might not be terribly competent if they double book it and never respond to Tess. Those are probably meant to be Red Herrings to give the impression that Keith rented it out to lure in Tess. About two weeks had elapsed after Tess and Keith disappeared and A.J. came back, but apparently no one noticed or went looking for them.
• How would Frank be able to make a whole tunnel system in the basement?
  • He dug it.
  • Perhaps it already existed before he ever bought the house. He could've chosen it specifically because he knew the tunnels would be useful to him. Though how he knew about it beforehand is anyone's guess.
    • He might have commissioned it as some sort of bomb shelter. His part seems to be taking place in the 1960s or 1970s when that was all the rage.
• The Mother doesn't wears clothes, and Detroit gets below freezing for much of winter. How does she venture outside during that time? And if she doesn't, who's getting supplies if Frank is bedridden?
  • That was perhaps why she (or Frank?) was going upstairs to the rest of the house while Keith and Tess were asleep. She takes food and other supplies from upstairs, meaning she can stay inside the (presumably heated) house. It also seems plausible that Frank had a serious stockpile of supplies and heating set up, because he knew that he would be keeping captives for a long time and year-round, so it may actually be relatively warm down there.
    • The house is repeatedly said to be rarely rented out, often going weeks or more without a rental, and it's unlikely that the rare people who do stay at the house stock it with much food to steal. And even if Frank had an initial stockpile of food, it would only last so long before going rancid. It seems like AJ has owned the place for years. So it seems pretty likely that the Mother wouldn't be able to go for months on end without foraging.
  • Given that the Mother is also extremely fast and seems to have evolved differently due to being underground, it's possible that she has adapted to not need clothes for warmth.
    • Mammals that adapt to cold weathers have a layer of blubber and/or a fur coat, and the Mother has neither. She might hibernate, but we see no evidence of that, and that wouldn't explain how Frank survives.
• How has generations of inbreeding made The Mother capable of the kinds of superhuman feats of strength and durability she performs in the film? She survives being hit by a car and falling off a high tower, and she’s strong enough to smash a man’s head in, rip a man’s arm off, as well as lift a man off the ground and tear his head in half.
  • Yes, we're meant to believe that her inbred genetics and harsh lifestyle have made her capable of superhuman feats. It's some real Artistic License – Biology.
  • It's one of those Hollywood tropes. There was an episode of The X-Files called "Home" that basically ran on the same general idea.
  • Dude, it's a pretty common trope for incest in horror films to result in near superhuman strength. Have you seen the Wrong Turn films?
• Where did that milk come from?
  • Either it’s decades old (we can assume Frank doesn’t leave the house anymore), or it’s the mother’s- leading back to the implication that the mother has actually had children, at a very young age.
    • Andre does seem to mention or imply that the Mother comes out at night, so presumably she can go steal supplies.
• Why didn't the Mother kill Tess and Keith the first night they were in the house? She clearly came upstairs since Tess hears her growl.
  • She probably did not kill them because she saw them as her new "babies". Though this does not explain why she later kills Keith instead of capturing him.
    • Keith probably pissed her off enough for her to kill him by struggling and shouting . This is presumably what Tess was warning A.J. about.
• If the basement door locks from the outside, and also closes by itself, then how did the Mother get out of the basement?
  • Frank might keep key to that door for her foraging missions.
• How did Keith end up so far down in the tunnels? So he went down, saw that Tess was telling the truth about the rape-room. Tess then asks him if he's seen it, and he replies "yeah" in a somewhat casual voice. Then I suppose he looks around, spots the second hidden door, opens it (without saying anything to Tess?), and his curiosity get the better of him and he decides to venture down using his unseen phone's flashlight as illumination? Not impossible, but what sane person goes down such a massive blind alley (when they were told they had only thirty seconds) after finding the proof that their companion's fears of some violent psycho having lived in the house at some point are justified?
  • When Tess finds Keith and asks him why he came down into the tunnels, he says that someone bit him. My interpretation was that just as Keith was about to go back upstairs, the Mother attacked him and brought him down into the tunnels.