Book excerpt: Hundreds of people slam through its doors every day: gun-shot cops, battered kids, drug addicts, and suicides, destitute drunks, homeless people, AIDS sufferers, and accident victims. It's a bizarre parade of humanity looking for help -- in the one place they know they can find it. Welcome to the frontline trenches of medicine: the emergency room of the legendary Bellevue Hospital. Here, an army of doctors and nurses faces the onslaught of young and old, rich and ragged, sick and dying. All day, all night. All year. This is their story -- an around-the-clock drama of the unexpected: a crane falling on a hapless pedestrian; a crazed executive wearing two-thirds of a three-piece suit; a pretty paralegal aide struggling with an on-the-job cocaine overdose; a trauma victim of an East River helicopter crash clinging to life. It's terrifying, tragic, triumphant ... and true.