Let the Right One In is Swedish romantic horror film directed by Tomas Alfredson and based on the John Ajvide Lindqvist's novel of the same name. The film tells the story of a bullied 12-year-old boy named Oskar who develops a romantic bond with a young girl named Eli. On realising that Eli is a bloodthirsty vampire, Oskar forgives her and declares that their true natures coincide; that is to say, Oskar wants to kill his tormentors and the girl needs to kill to survive.
But how does this coincide with Us?
Adelaide and Red's dual natures inform how they kill and why. As with Let the Right One In, neither character's motivation to kill is wholly villainous or virtuous. We initially think of Adelaide as the hero and Red as the villain even though the revelatory twist of their intertwined past places why each woman kills into more of a grey area than we initially believe. Even still, Adelaide and Red both commit horrific acts to further their respective causes. For Adelaide, this means kidnapping and killing to make a better life for herself and her middle-class family. For Red, this means stageing an uprising to kill millions of people in an effort to take back what she believes rightfully belongs to her. Though the audience is prone to negatively judge Red's actions — just as we initially do when we understand Eli is a vampire — the truth is that there is good and bad in all of us.
For those interested in additional research, Cloverfield director Matt Reeves wrote and directed an English-language version in 2010 titled Let Me In.
You can watch Let The Right One In on Hulu.