The greatest unnameable fear for all of us who are parents is that of losing a child. We hear about it in others, we read about it in the papers and a cold chill touches us. The most common deaths are sudden in accidents but many parents have to cope with the long drawn-out trauma, alternating hope and fear, of sickness. No-one can ever know if or when or where they may experience the policeman at the door or the embarrassed compassion in the doctor's face.