History Literature / WeHaveAlwaysLivedInTheCastle

* AdaptedOut: Merricat and Constance's younger brother Thomas is completely absent from the film. He isn't even pictured in the Blackwood family portrait that is prominently displayed in several scenes.
** Though the filmmakers seemed to have taken inspiration from him when they named the misbehaving, obnoxious little boy in the grocery store Thomas.

* DaylightHorror: In spite of its dark reputation, the Blackwood House is always described with literal sunlight streaming through every room, particularly Constance's kitchen and garden. The story itself takes place during one particularly beautiful week in spring.
** Uncle Julian notes on several occasions that the Blackwoods died on a bright, beautiful summer day when no one would suspect anything amiss.
* DeathByAdaptation: In the film version, [[spoiler: Merricat murders Charles.]]

* PerfectPoison: [[spoiler:The sugar that the Blackwoods had sprinkled on their blackberries that night had been laced with arsenic. This also worked to spare Constance (though also pinning her as the culprit), since Merricat knew her sister didn't like sugar.]]

** [[spoiler: Merricat commits murder and not only gets away with it without being suspected, but ends up with what, for her, is the happiest possible outcome: she has her beloved sister all to herself and never has to leave home again.]]

* LongTitle: Merricat compares Blackwood House to "a castle, turreted and open to the sky" [[spoiler:after the house is partially destroyed by fire.]]

* {{Foreshadowing}}: Merricat lists the "death cup" mushroom as one of the things she likes in the page quote, and has a habit of describing poisonous plants as an ImpliedDeathThreat whenever Charles is eating something. [[spoiler:Considering her fascination with anything poisonous, it's only fitting that she was the one who poisoned her family.]]