But it is a curve each of them feels, unmistakably. It is the parabola. They must have guessed, once or twice--guessed and refused to believe--that everything, always, collectively, had been moving toward that purified shape latent in the sky, that shape of no surprise, no second chances, no return. Yet they do move forever under it, reserved for its own black-and-white bad news certainly as if it were the Rainbow, and they its children. . .