"George moved slowly after them and his feet dragged heavily"
This is a part of narration toward the end of the chapter. Curley forces George to come with the mob or else he will think that he was a part of the death. It sets the tone and mood of the next chapter. It creates a dark and terrible vibe. I think that this foreshadows a difficult a really bad event will happen in the next chapter. George is truly scared for Lennie and feels that something bad will happen to him because he killed Curley's wife.
This is a part of narration toward the end of the chapter. Curley forces George to come with the mob or else he will think that he was a part of the death. It sets the tone and mood of the next chapter. It creates a dark and terrible vibe. I think that this foreshadows a difficult a really bad event will happen in the next chapter. George is truly scared for Lennie and feels that something bad will happen to him because he killed Curley's wife.