Ray Stussy and Nikki Swango unsuccessfully try to rob Ray 's twin brother Emmit .
It follows the lives of a couple , Ray Stussy ( Ewan McGregor ) and Nikki Swango ( Mary Elizabeth Winstead ) , who , after unsuccessfully trying to rob Ray 's twin brother Emmit ( also played by McGregor ) , become involved in a double murder case , including an old man with a mysterious past whose stepdaughter Gloria Burgle ( Carrie Coon ) is a policewoman .