When an actress falls in love with her co-star, she finds her life is becoming much like the film she is starring in, which is based on a Polish film that was never finished due to horrible tragedies.
Swanson stars as fading film star Norma Desmond and Holden plays the struggling writer who is held in thrall by her madness. Von Stroheim plays Desmond's discoverer, ex-husband, and butler.
An actor and actress have an adulterous affair while playing the screen roles of an engaged scientist and the tainted woman with whom he becomes obsessed.