What is the significance of the subway? How does it contrast with the city? How does it contrast with the forest? How does it affect the mood of the story?

The subway is a forbidden location, but Equality cannot resist the things he finds there. Advanced technology.... things forgotten.... all there to be remembered and studied. The subway is a place of isolation in a world where there's no such thing as being alone. It's filled with a wealth of knowledge... knowledge just waiting to be rediscovered. The city has none of these things... the scholars have allowed these discoveries to be forgotten. In the forest, Equality is challenged by the same types of discoveries.... and he begins to learn all over again. All of these things together create a mood of hope and anticipation.