In 1917, Baby Jane Hudson is a well-known Vaudeville child actor while her older sister Blanche lives in her shadow. By 1935, their fortunes have reversed: Blanche is a successful film actress and Jane lives in obscurity, her films having failed. One night, Jane, able to imitate Blanche's voice perfectly, mocks her at a party. That same night, Blanche is paralyzed from the waist down in a mysterious car accident that is unofficially blamed on Jane, who is found three days later in a drunken stupor.