<span>The setting of this excerpt is a dense, secluded forest through which no travelers seem to want to venture. The strange, large figure in the road makes the protagonist paranoid and afraid, which further builds the tension and fear in the story from the previous excerpt.</span>
We need to be able to read the story before we answer.
Very
Very is the adverb that is modifying another adverb. In this sentence, the adverbs are usually, quickly, very, and carefully. Usually modifies the verb moves telling how often he moves the eggs. Quickly and carefully both modify the verb moves as well. They describe how he moves - quickly and carefully. Very is an adverb that clarifies how carefully the speaker is moving.