I understand why Hitchcock liked to use movie stars. It was a quick way to connect a character to the audience without having to provide a lot of exposition. It can also change the denouement of the movie. (I am thinking specifically about Ivor Novello vs Laird Cregar in The Lodger and Cary Grant in Suspicion.) So my question is... if you don't have a sense of the persona of the stars in the movie, how do you make that connection, understand the motivations of the characters, and see
why Hitchcock chose to end the movie the way he did?