When a new influenza virus emerges that is able to be transmitted between humans, it spreads globally as a pandemic, often with high mortality. Enormous social disruption and substantial economic cost can result. The 1918 Spanish influenza pandemic was undoubtedly the most devastating influenza pandemic to date, and it has been Dr Robert Webster’s life’s work to figure out how and why. In so doing he has made a remarkable contribution to our understanding of the evolution of influenza viruses and how to control them. A century on, Flu Hunter is a gripping account of the tenacious scientific detective work involved in revealing the secrets of this killer virus. Dubbed ‘Flu Hunter’ by Smithsonian Magazine in 2006, Dr Webster began his research in the early 1960s with the insight that the natural ecology of most influenza viruses is among wild aquatic birds. Painstaking tracking and testing of thousands of birds eventually led him and the other scientists involved to establish a link between these bird virus ‘reservoirs’ and human influenza pandemics. Some of this fascinating scientific work involved exhuming bodies of Spanish flu victims from the Arctic permafrost in a search for tissue samples containing genetic material from the virus. Could a global influenza pandemic occur again? Webster’s warning is clear: ‘... it is not only possible, it is just a matter of when.’