300 years ago the only way for doctors to work out what made people tick was to get a body and delve around inside. It was a time of great discovery, but it also marked the beginning of the illicit trade in bodies. However, is this really a thing of the past? Companies trading in body parts today can make up to US$5,000 for a whole body. They usually source their bodies by placing adverts in care homes and hospitals. But with demand high, some unscrupulous traders have used the bodies of those who haven't given their permission, with devastating consequences. Horizon investigates this gruesome trade.