George and Lennie are good friends that travel to a ranch to work. George is the smart friend and Lennie is the slower friend that thinks without really thinking. They end up at the river and Lennie is found with a dead mouse and George yells at him.
When they're in the ranch they start to work and they meet new people. The ranch has characters that have gotten beaten down by life and have no where to work. At the ranch, they met Slim, The Boss, Carlson, Curley, and Curley's wife.
Candy owns a dog that is weak and old that Carlson wants to kill but doesn't want to do it. He convinces Candy to kill the dog but Candy doesn't want to do it. After all, Carlson kills the dog.
George goes and talks to Crook about how he feels lonely and has no one to talk to. Crook lets him in his house and he also starts talking about how he feels lonely and has no one to talk to all though Crook isn't that nice.
Lennie gets left in the barn alone and then looks around and finds a dead puppy. He gets mad because he thinks that George won't let him pet any of the rabbits. Later Curley's wife comes to talk to him and he freaks out and breaks her neck.
When everyone finds out that that Curley's wife is dead, Curley gets mad and goes out to look for Lennie. George goes and finds him then explains what happened. As he is explaining himself, George points the gun to Lennie's head and shoots him.