Sperm whales were hunted mercilessly – as captured in Melville's Moby Dick – to provide lubricant and lighting oil. But could other aspects of the classic novel also be factual? How is it connected with the Chilean island of Mocha? Did these vast creatures, with their huge brains and devastating biosonar, learn to fight back? Scientific reconstructions evaluate their ability to ram and sink sturdy whaling ships – but how did they recognize these particular vessels?