I think that a statement might be made about the nature of hidden relationships ending in disaster. It seems to me that one of the driving forces behind Fitzgerald's work is the idea of transparency and being open about reality and the conditions that surround it. One of the striking features of this would be the ending when Nick rejects all of the trappings of the upper class and goes back to the Midwest, a statement in favor of openness and transparency as opposed to the covert destruction on personal levels that wealth seems to bring to the people in East Egg. We can see this in the relationship between Jay and Daisy. Both of them pursue their relationship under "cloak and dagger" circumstances, with each pursuing their own agenda. Daisy simply likes to be wooed. There might be some feelings present, but they are not strong enough to force her leaving of Tom and his money and the life to which she has become so accustomed. Gatsby might be chasing a dream or an illusion, and yet he does so without openly declaring it. He is content with its pursuit being done hidden from the eyes of other. The clandestine and opaque nature of their relationship might be a setting where Fitzgerald is echoing Justice Brandeis in that, "Sunlight is the best disinfectant." The lack of "sunlight" in the relationship shared by Daisy and Jay might be an instance where the lack of it caused a disease to grow and fester, resulting in Gatsby's death due to misunderstanding and a lack of understanding.