coup de théâtre vs plot twist

coup de théâtre

noun
  • A sudden or unexpected event in a play, pulled off by the author, the director, or even an actor. 

  • A theatrical trick or gesture, something staged for dramatic effect. 

plot twist

noun
  • A change in the direction or expected outcome of the plot of a film, novel, or other narrative work. 

How often have the words coup de théâtre and plot twist occurred in a corpus of books? (source: Google Ngram Viewer )