lead into vs prologue

lead into

prologue

verb
  • To introduce with a formal preface, or prologue. 

noun
  • A speech or section used as an introduction, especially to a play or novel. 

  • A component of a computer program that prepares the computer to execute a routine. 

  • One who delivers a prologue. 

  • An individual time trial before a stage race, used to determine which rider wears the leader's jersey on the first stage. 

How often have the words lead into and prologue occurred in a corpus of books? (source: Google Ngram Viewer )