In 1959, the peaceful neighborhood of only Caucasian, Suburbicon, is troubled by the arrival of an African-American family, the Mayer family. One night the Lodge family house is invaded by two thieves who bind all family members and kill Gardner Lodge’s wife, Rose, with an overdose of chloroform. Subsequently, Rose’s twin sister, Margaret, moves into her home to take care of the child’s family, Nicky. Not too long, and Margaret begins to turn into Rose, painting her hair like hers and sleeping with Gardner.
As tensions grow between suburban residents and their new African-American neighbors, charismatic insurance agent Bud Cooper arrives on a day when Gardner is not home and begins to question Margaret, trying to understand some aspects of Rose’s life insurance that Gardner had requested shortly after she died.
The conversation begins pretty harmless, but Cooper gets more and more suspicious when Margaret refers to her and Garder as a couple, and then she puts her out of the house. Meanwhile, the two thieves who killed Rose are angry that Nicky sneaked into the police identification room where Gardner and Margaret denied that they were in the house at the time, but the kid admits it. From that moment on, things begin to complicate for the Lodge family, and it is becoming increasingly clear that Rose’s death was not even accidental.