"Essence and emblem of life - feared, revered, mythologized, and used in magic and medicine from earliest times - human blood is now the center of a huge, secretive, and often dangerous worldwide commerce. It is a commerce whose impact upon humanity rivals that of any other business - millions of lives have been saved by blood and its various derivatives, and tens of thousands of lives have been lost. Douglas Starr tells how this came to be, in a...