: A local math professor explains that the cellar serves as a physical manifestation of a complex equation designed to bridge our world with a hellish realm. The Resolution
The inciting incident occurs when the family moves into an old Irish manor.
: Ellie and her brother find a gramophone playing a recording of someone reciting mathematical formulas and counting.
: The house was built by John Fetherston, a mathematician who used non-Euclidean geometry and alchemy to open a portal to another dimension.
: Keira hears Ellie count past ten—continuing well into the dozens—as if descending an infinite staircase before the line goes dead. The Investigation & "Satanic Math"
: During a blackout, Keira guides Ellie to the cellar via phone to reset the breaker. She tells her to count the ten steps down to help her fear of the dark.