One of the most famous final lines in all of literature is F. Scott Fitzgerald’s coda to The Great Gatsby: “So we beat on, boats against the current, borne back ceaselessly into the past.” It is as close to perfect an ending as any American writer has yet devised. Yet it’s difficult not to wonder how differently we might regard that work, had Fitzgerald heeded Zelda’s suggestion to follow that line with, “And then Nick woke up. It had all been a dream. Or had it…?”