WARNING: The following article contains spoilers for The Haunting of Hill House, streaming now on Netflix.
One of the biggest mysteries throughout the 10 episodes of Netflix's The Haunting of Hill House is the Red Room in the home purchased by the Crain family. From the first episode, we see it's tied to the death of mother Olivia Crain (Carlo Gugino), and as the series progresses, it becomes apparent how it influenced the lives of her children over the years, plaguing them like a bad dream.
In the finale, "Silence Lay Steadily," we finally learn the purpose of this room, and come to find out it's much more than four walls and a red door.
It's a Living Thing
When the youngest Crain daughter, Nell (Victoria Pedretti), returns after death to rescue her siblings trapped in the Red Room after returning as adults to Hill House, she fills them in on its true purpose. She initially likens it to a "person" longing to keep everyone who's lived in Hill House trapped forever. That's why we see ghosts from different eras haunting the place, as they fell victim to it.
The Red Room traps people by acting as a shape-shifter, taking the form of whatever room the house's inhabitants need to feel comfortable, similar to the Room of Requirement from the Harry Potter franchise. In early episodes, it's a toy room for young Nell, a game room for Steven, a tree house for Luke, a dance studio for Theo, a family room for Shirley, and a reading room for mother Olivia. "But it was always," Nell recalls, "the Red Room."
Basically, the Red Room becomes a best friend, a place of solitude and comfort, in order to establish a meaningful connection to an inhabitant. “Mom says that a house is like a body. And that every house has eyes, and bones, and skin, and a face,” Nell elaborates on the Red Room's motives. “This room is like the heart of the house. No, not a heart, a stomach," confirming people like the Crains are just food for the house to digest, providing it fuel to live on.
It Paints the Real World As Hell
That's only part of a two-pronged attack, however, because the Red Room has another aspect to it that creates a desire within the people living inside to want to stay at Hill House forever. Apart from luring you into this false utopia inside its walls, the Red Room makes the inhabitants fear -- and ,in extreme cases, hate -- the real world.
We see this in the finale when it makes the now-adult Crain children hallucinate about life outside the house, exploiting guilt about issues in their lives to make them believe that existence outside Hill House is a nightmare from which they need to wake. From Luke's inability to overcome addiction to Steven's fear of passing on the family "curse" to any children he might have to Shirley's infidelity to Theo's failure to establish a loving connection anyone, the Red Room tries to prevent the Crains from returning to the real world by reminding them how dark it is.
By doing so, it does its best to convince them to stay inside, goading them into thinking that, if they die here, they can live for eternity in their own version of paradise with the ones they love most -- as seen in the flashback where Olivia tried to poison her twins just before she died, so they could live on in an infinite tea party.
Now available on Netflix, The Haunting of Hill House stars Michiel Huisman, Carla Gugino, Henry Thomas, Elizabeth Reaser, Kate Siegel, Timothy Hutton, Oliver Jackson-Cohen, Lulu Wilson, Victoria Pedretti, Mckenna Grace, Violet McGraw, Paxton Singleton and Julian Hilliard, with Annabeth Gish.