A DARK HELICOPTER chugged low and obnoxiously against fluffy white clouds in a high blue sky. The air had just the proper bite to offset the full sun’s warmth, an ideal autumn moment. But the clouds smoothed up and fused together until a swift-arriving dimness covered midday. The afternoon improved briefly, but it irregularly trended toward the worse, under velvety humidity. The clouds kept moving, feathery and pale in the north and a clotted, faintly rusty gray in the south. Here and there on the ground lay the seasons’s self-reaped harvest: elongated acorns massing by the curb, black-splotched red crabapples catching the eye by the path, Osage oranges shining brighter green than the lawn they were scattered around. A cloud of midges floated against a backdrop of yellow leaves. A black cat on a leash walked to the foot of a tree and considered climbing. Children in and out of costume scampered around the crown of the Great Hill; a wedding party blew bubbles down by the Loch. Asters traced the edges of the groves and walkways with glimmering pale purple. The varied sky went fully gray again, and the arrival of the night rain made it hard to get to sleep till the window was closed.