Terror stole the old dog's soul. An evil, living entity, it clutched his senses and he was unable to move. Surely the one who'd loved him for so long would come back. Surely she would be here in time. He knew from the cries of the others before him that the big metal box was the end. That he wouldn't be able to breathe. That he'd die. He knew, but could not know why. His empty stomach knotted and lurched as the smell of death permeated the air. He shrank into the back of the cage, and waited. Waited for her. Tried to will her shadow across the doorstep of the shelter. 

That night, his last ... the dog dreamed of playing with frisbees. Chasing tennis balls. He dreamed of running with the wind at  his back, and chasing butterflies. His memory took him back to belly rubs and swimming in ponds. And the ecstasy of soft hands that fed him treats ... that caressed his face and ears. He whimpered and barked, and his powerful legs took him far from the horror of the silver box. Away, into the warming sun. Into the arms of angels ... who sang him a lullaby.