We gathered in a field southwest of town,several hundred hauling coolersand folding chairs along a gravel roaddry in August, two ruts of soft dustthat soaked into our clothesand rose in plumes behind us.By noon we could discern their massive coilsemerging from a bale of cloud,scales scattering crescent dapplesthrough walnut fronds,the light polarized, each leaf tip in focus.As their bodies blotted out the sun,the forest faded to silverpoint.A current of cool airextended from the bottomlandsan intimation of October,and the bowl of sky deepenedits celestial archaeology.Their tails, like banners of a vast army,swept past Orion and his retinueto sighs and scattered applause,the faint wail of a child crying.In half an hour they had passed onin search of deep waters.Before our company dispersed,dust whirling in the wind,we planned to meet again in seven yearsfor the next known migration.Sunlight flashed on windshieldsand caught along the riverbanka cloudy, keeled scaleabout the size of a dinner plate,cool as blanc de Chinein the heat of the afternoon.