Later, Ilsa enters Rick’s place and recognizes the piano player. She says, “Play it, Sam.” Sam recognizes her and tells her that she’s bad luck to Rick, but plays “As Time Goes By” anyway. Then Rick enters and tells Sam, “I thought I told you never to play that—“ And then he sees Ilsa. His angry look and the entire scene imply that there’s a lot of history between these two people. This is the Big Event. It’s so big that no one dares leave the movie theater for popcorn again until the movie’s over.