The film is set in Los Alamos, New Mexico, in the early 1980s. Owen (played by Kodi Smit-McPhee) is a lonely 12-year-old boy who is frequently bullied at school. One night, he meets Abby (played by Chloë Grace Moretz), a mysterious girl who moves in next door with her father, Thomas (played by Richard Jenkins).
In the climax, Owen and Abby strike up an unlikely friendship, and Owen becomes infatuated with her. However, he soon discovers that Abby is not an ordinary girl—she is a vampire who survives by drinking human blood. Despite this revelation, Owen is drawn to Abby and continues to spend time with her.
As the plot unfolds, Abby’s need for blood becomes increasingly urgent, and Thomas resorts to murdering people to feed her. Meanwhile, Owen struggles with his feelings for Abby and the knowledge of what she is.
In the resolution, Abby’s secret is exposed when Thomas is captured and interrogated by the police. In a desperate attempt to protect Abby, Thomas pours acid on his face, sacrificing himself to prevent the police from learning the truth about Abby’s vampiric nature.
The film concludes with Owen and Abby’s bond growing stronger as they contemplate their uncertain future together. Despite the challenges they face, they find solace in each other’s company and the knowledge that they are not alone in the world.
“Let Me In” is praised for its atmospheric cinematography, strong performances, and poignant exploration of themes such as loneliness, friendship, and the nature of evil. It is a haunting and emotionally resonant film that offers a fresh take on the vampire genre.