I'll start. I got this concept from a TV show.
In the shocking climax of the film, Palpatine reveals that it is Chewbacca who is truly Luke's father!! Chewbacca appears out of nowhere and growls. "Son!" Luke cries "Father," and there is a dramatic moment before Chewbacca picks up Palpatine and throws him over the railing. Darth Vader runs.