All of us have benefitted at some stage in our lives from modern medicines, the products of scientific research and discovery developed by the pharmaceutical industry. This book is for those who are curious to know where these medicines come from, who discovered them, and in what context. Starting with a few chance observations made by dedicated and inspired scientists working in isolation, it chronicles the development of therapeutics in medical practice and in parallel the emergence of the multi-million dollar pharmaceutical industry. The approach is historical, making the science accessible for the lay reader by explaining and building successive stages in our understanding of the disease process and the action of drugs and candidates for drugs, until we arrive at the complex whole. Profound social changes have resulted from the development of new medicines, just as social pressure has driven the research effort. Social context is a strong theme of the book, as is the character of the men and women who made it all happen. Dr Weatherall trained as a doctor before immunization for diphtheria and the other diseases which killed so many children became widely accepted. Without the power to cure brought by antibiotics and other modern drugs, the role of the doctor was very different. He brings to his account an understanding of the changes to all our lives that medicines have brought about, presenting a view of the hazards inevitable in using such powerful substances and of the dangers of accepting the illusions created by charlatans about treatments that have no demonstrable worth.