The "MacGuffin"

  The "MacGuffin" has appeared in several of Hitchcock's films, specifically in two of the films we've watched - "The 39 Steps" and "Notorious." In a minimum of fifty words, please define the term "MacGuffin" and then identify the MacGuffin in each of the above-stated films. There are several themes running through "Strangers on a Train." In a minimum of fifty words, pick your favorite based on the lecture and watching the film and illustrate it with two examples from the film.