Let's consider first what actually happens at the end of this story:
- Lennie accidentally kills Curley's wife and runs back to the streambed from the first scene in the novella.
- George, guessing where Lennie is, sends the lynching mob in the opposite direction and goes to find Lennie himself.
- Understanding that there is no way to solve this problem, but even more relevantly that Lennie will continue to do "a bad thing" everywhere they go, George resolutely tells Lennie to imagine their dream farm.
- George shoots Lennie in the back of the head. The sound of gunfire draws the lynchmob.
- George claims that Lennie was trying to take his gun, and Slim carefully leads him away, reassuring him that he has made the right choice.
Steinbeck's depiction of George depends on several different elements. I'll list a few and provide you with textual evidence of several of those examples; you can use those examples with evidence to guide you in selecting your own evidence for those examples without any.
- George's dialogue with Lennie reveals that George feels helpless and like he has no other option; he does not want to shoot Lennie, but he is realizing that it is the only thing to do. This is revealed mostly through descriptions of George's voice, not through his dialogue itself, which Steinbeck illustrates several times: "George said quietly," "he fell silent again," and "his voice was monotonous, had no emphasis" (50-51).
- George believes he is protecting Lennie by killing him, as revealed through his careful analysis of the lynch mob's proximity: "There were crashing footsteps in the brush now. George turned and looked towards them [...] The voices came close now. George raised his gun and listened to the voices" (51).
- George's actions following Lennie's murder reveal deep discomfort and unhappiness with what he has done.
- Slim's reaction to George indicates that George's self-loathing and unhappiness are easily identifiable to onlookers. His grief is apparent, despite the fact that he is supposed to be a strong, stern character without much emotion.