In the 16th century, when explorers travelled deep into the jungles of South America in search of gold and spices, they brought back many colourful tales of their adventures. None of these tales was more astonishing, or caused more concern, than that of the mystical properties of the substance with which the natives anointed their darts and arrows. They described terrible agonies inflicted by 'the flying death', caused by the magical arrow poison curare - their tales speaking of the victim's 'staring eyes bulging out of their sockets with terror', and of 'bellies rendered asunder'.

So begins the incredible true story of the discovery of one of the most important substances in medical science. Curare was to become the cornerstone of modern anaesthetics and in the hands of the most eminent naturalists and scientists schooled in the Western enlightenment it went on to provide the key to how we understand the human nervous system. It led directly to a host of drugs as diverse as Prozac, beta-blockers, Botox and diarrhoea pills - and more recently it has led to our understanding of Alzheimer's and Parkinson's disease.

Truly the equal of such milestones as Fleming's discovery of penicillin and Jenner's of vaccination, this is the story of bizarre research, outlandish experiments and modern miracles; of cunning explorers wrestling with giant reptiles in pursuit of specimens; of frighteningly deadly toxins and incredible life-giving discoveries. You will never look at your medicine bottle in the same way again...