In what way are you supposed to arrange them?
Even though the story revolves around the premise of the aunts' mercy killings, the central conflict is with Jonathan. Without Jonathan's arrival as the primary antagonist, there would be few to no real obstacles between Mortimer and his goal of protecting his aunts and committing Teddy.
I'm assuming that the answer is blanket because fog is often said to "cover the land like a blanket". May I ask what poem you are referring to? This would aid in answering the question. <span />