Loneliness is a burden we've all borne in one degree or another. It throws us back among our own personal resources, which, in the ordinary course of things are sufficient to sustain us. But there's nothing ordinary about the loneliness we're going to deal with here, even though two people share it. This is loneliness intolerably multiplied. Grace and Harry Clayton are returning from vacation, but they're exhausted. They've driven in one day, from Maine to Long Island...