'Abstract: April 2001. A beautiful Autumn day. The sun's rays still hold warmth; the air is crisp and clear. Our family is on a bush walk. Stephen and our two daughters run on ahead. We begin a steep incline, our feet crushing the fallen leaves underfoot. Soon Stephen lags behind. Striding ahead, I glance back over my shoulder and see him slowly negotiating the rough track. I notice that his right arm isn't swinging as he walks. A small flutter of fear floats nearby, but I push it resolutely away. Then I remember other barely perceptible changes - the way his foot sometimes drags a little when he walks, the disturbed sleep when his body twitches restlessly in the night. Above me, the sun passes behind a cloud. The day has suddenly turned cold.' (Author's introduction)