The biggest event in Chapter 3 is the execution of Candy's old dog. Carlson is insisting that the dog must die. Candy is putting up a feeble defense, but he has everybody in the bunkhouse against him, including Slim, whose "opinions were law." Slim says:
"Carl's right, Candy. That dog ain't no good to himself. I wisht somebody'd shoot me if I got old an' a cripple."
All the men are gathered in the bunkhouse, and all are aware of the suffering Candy is going through. But there is nobody to defend the dog. The men are like a jury which has already reached a unanimous decision. Finally Candy says, "Awright--take 'im."
Candy lies on his bunk and stares at the ceiling. After Carlson takes the old dog outside, Candy is waiting to hear the shot that will mean the end of his old friend and companion. All the other men are waiting with him, knowing what the old man is going through. The men are nervous, trying to make conversation, perhaps feeling a little guilty about passing a death sentence on poor Candy's dog.
A shot sounded in the distance. The men looked quickly at the old man. Every head turned toward him.
For a moment he continued to stare at the ceiling. Then he rolled slowly over and faced the wall and lay silent.
This is a moment of pity. These tough men all feel sorry for Candy because they know how he feels to lose the only friend he had in the world. They know how hard it must have been for him to say, "Awright--take 'im." The reader shares Candy's feelings and the feelings of all the men in the bunkhouse.
Steinbeck does not have one big conflict running throughout the novel. Instead he has created dramatic interest by having numerous minor conflicts, with at least one in every chapter. For example, George has a conflict with the Boss because he arrives late for work and because the Boss is suspicious of George's relationship with Lennie. The book is full of conflicts, such as the fight between Lennie and Curley and the argument between Crooks and Curley's wife. In Chapter 3 there is the conflict between Candy and Carlson over the old dog. Candy is destined to lose because everybody is on Carlson's side.
Steinbeck's purpose in dramatizing a prolonged conflict over the fate of Candy's old dog is to show, in a naturalistic way, that Carlson possesses a Luger. The reader learns, along with George, how to kill painlessly with a single shot. He also sees where Carlson keeps his German handgun, and how the automatic weapon works. Later George will use the Luger to kill Lennie painlessly at the riverside campsite. But the existence of the gun had to be established. In Hollywood parlance, the display of the gun Carlson uses to kill Candy's dog would be called a "plant." A Luger is a distinctive-looking handgun. When George pulls it out of his side pocket, everyone in the audience at the play Steinbeck intended to produce in New York, and for which the short novel served as a detailed "treatment," will immediately recognize it as Carlson's gun and will understand that George stole it with the intention of killing Lennie.
"We gonna get a little place," George began. He reached in his side pocket and brought out Carlson's Luger.; he snapped off the safety, and the hand and gun lay on the ground behind Lennie's back. He looked at the back of Lennie's head, at the place where the spine and skull were joined.
George knows where the Luger was kept under Carlson's bunk. He knows how to use it. He knows where to point it in order to kill his friend painlessly with a single shot.
The crash of the shot rolled up the hills and rolled down again. Lennie jarred, and then settled slowly forward to the sand, and he lay without quivering.