What symbols and irony occur in Chapter Three in Of Mice and Men?How would I summarize the chapter?

Chapter three begins with George talking to Slim. George says he knew Lennie’s Aunt Clara when he was younger, promised to care for Lennie when she died. He says that Lennie is extremely loyal. He explains that they left the last town because Lennie touched a girl’s dress. When she screamed, Lennie panicked and wouldn’t let go until George hit him in the head with a board. The girl accused Lennie of raping her, so they left in order to save Lennie’s life. Lennie enters the bunkhouse with a newborn puppy, but George won’t let him keep it, telling Slim that Lennie is too rough and will kill it. Candy enters with his dog, and Carlson tells Candy he needs to kill the old dog. The men talk about how by shooting the dog in the back of the head will cause instant pain free death, foreshadowing the end of the novel. Candy gives in and Carlson takes the dog out. During a card game, Curly comes looking for his wife. He leaves to confront Slim. When everyone is gone, George talks about owning a farm. Candy overhears and tells them he will give them his savings if he can share their dream. The men come back and an argument ensues between Carlson and Curly. Curly becomes extremely angry, turning to Lennie who is smiling to himself. Curly punches Lennie repeatedly until George yells at Lennie to “get him.” Lennie grabs Curly’s hand and crushes it. When George tells Lennie to let go, his only worry is that George will not let him feed the rabbits.