Mammoths and sabertooth cats are but two icons of an assemblage of large animals, or megafauna, that disappeared between roughly 50,000 to 12,000 years ago. As with all mass extinctions, several explanations have been put forward, but one man and his idea take centre stage in these discussions: Paul S. Martin’s overkill hypothesis. In End of the Megafauna, palaeomammalogist Ross D.E. MacPhee carefully scrutinises this idea, weighs up the arguments for and against, and explains its enduring allure. To quote Huxley, is this another example of “the slaying of a beautiful hypothesis by an ugly fact”?