The theme of Robert Frost's poem is the destuctive potential of hatred and desire. In his poem, Frost explores with amazingly eloquent brevity two forces which have the potential to bring destruction to the world. The first of these two is desire, which Frost likens in heat and intensity to fire.
Pronouns are words used to replace nouns in a sentence. This is why instead of using "Zoe" for the second time in the sentence. Zoe can be substituted with :she".
