The anthropologist and journalist Joris Luyendijk knew as much as any neighbor's son about the mysteries of financial activity: just a couple of topics. Bankers were for him sharks who hatch sinister intrigues in a world happily alien to ours. Until he was commissioned to explore the waters of money. Armed with the instruments of social science and the nose of a bloodhound, our audacious researcher fearlessly threw himself into the shark tank, also known as City of London. During two years of immersion he conversed with executives and secretaries, with enthusiasts and skeptics, with winners and losers; he questioned stockbrokers, speculators, computer scientists, accountants and public relations: more than two hundred individuals who (often without realizing it) broke the code of silence to bring to light the entrails of the beast.