Out of concern for Lennie, George advices him to come to hide there if he ever got into trouble. After all they did get kicked out of the last town they were in because Lennie touched a girls red skirt and she accused him of rape. This scene foreshadows the end of the book.
Lennie is mesmerized by Curley's wife and can't stop looking at her. George tells him to stop because everything he touches he breaks. However, when Lennie wants something he won't stop until he gets it.
Carlson is trying to convince Candy to shot his dog because he's suffering of old age. Candy agrees and is devistated because he has been with the dog since he was a puppy. This foreshadows how Carlson kills things with his gun.
Crooks tells Lennie about his childhood and his up and downs in life. After Lennie tells Crooks all about his dream, Crooks suddenly remembers his childhood. He knows what its like to have your dream and then have it taken away. As a result Crooks doesn't want to have anything to do with Lennie's dream because of the fear of failure.
Lennie accidentally kills Curly's wife after she lets yells for help. Curley's wife sits down with Lennie and speaks about her past with him. She offers to let him feel her hair but after getting too aggressive, she yells for help. Lennies trys to make her stop by holding her down, instead of stopping her from yelling her he snaps her neck.
George kills Lennie quickly with a gun to spare him from a painful death from the mob. George knows that Lennie didn't mean to kill Curley's wife and it was not his intention.