John Steinbeck's short story "Of Mice and Men" is a perfect literary example of well-done foreshadowing. The story follows George and his mentally handicapped friend Lennie. George has agreed to take care of Lennie because he brings him joy and a sense of purpose. Although he means no harm, Lennie is unaware of his own strength and accidently kills animals and ultimately a woman. Since he is responsible for Lennie's warfare, George feels he is also responsible for putting an end to Lennie's crimes.
There are several examples of foreshadowing in "Of Mice and Men." The first series of examples include the death of the mouse in the first chapter, the death of the pup, and when Curley's wife tells Lennie to stroke her hair. All three of these scenes point to the death of Curley's wife.
The most significant example of this technique is the killing of Candy's old dog. Candy knows that his dog must be put to death; however he cannot bear to kill it himself. Curley kills the dog for Candy as Candy closes his eyes. After hearing the shot, Candy shows no emotion. Later Candy regrets that he didn't kill his dog himself.
This entire scene points to Lennie's death. Yet unlike Candy, George has the strength to kill his own "pet" and shoots Lennie in the back of the head using Curley's gun. The killing of the dog foreshadows George's actions as well as his emotions. It helps the reader understand the climax as action.