After Lennie ended up killing Curley's wife, he runs away into the brush where George told him to hide if he got in trouble. While he is hiding in the brush he begins to talk to himself. Then out of nowhere, he see's a mysterious person pop out of his head.
George won' let me tend no rabbits now!
At first, aunt Clara popped out of Lennie's head. She was telling him that he makes George miserable, and if George didn't have to take care of Lennie he would be having the time of his life. This makes Lennie really sad, but eventually she goes away. Then, out pops a rabbit from Lennie's head. He makes a fool out of him by telling him he would never be able to tend rabbits and that he is pathetic. This makes Lennie start to yell George's name.
But, but I can go to cave! GEORGE!!
You make George Miserable!
George ends up coming over to Lennie asking what he was yelling about. This makes Lennie slightly confused but happy that George is now there with him. George asks Lennie to look out to the river as he and Lennie talk about their future and what they will have when they get there. This makes Lennie very excited, but strangley, George becomes sad. Lennie asks George a couple times if he's mad, but he says he isn't. George and Lennie say that they have each other as family because no one else will take them, then George lifts a gun up to the back of Lennie's head and shoots him.