The Understudy follows Eleanor Hart, a young actress who finally gets her big break when the lead star, Victoria Hale, mysteriously collapses. As Eleanor steps into Victoria’s role, strange events unfold whispers in the theater, moving reflections, and warnings written in mirrors. She becomes haunted by the sense that Victoria never truly left. During a live performance, the reflection of Victoria steps out of the mirror, and Eleanor collapses. When she wakes in the hospital, everyone calls her Victoria Hale. Meanwhile, the real Eleanor opens her eyes elsewhere, trapped in Victoria’s place the understudy now permanently replaced.
