This is a charmingly written memoir of the career of Alfred Sommer, the man who developed epidemiology into a vital tool for global health policy. In each of the ten ‘lessons’, we travel with him to a country suffering a health crisis, and learn how it was resolved. It is humble in tone, which I found misleading – it becomes clear that the author is downplaying great personal gifts of insight and persuasion, and also his personal bravery as he ventures into areas of political instability and infectious disease. A lesser man simply would not have achieved what he did, I feel. The text is dotted heavily with mostly irrelevant personal anecdotes, which distract from the message of each epidemiological technique, but are undoubtedly sometimes fun to read. My favourite anecdote is the one about a friend’s wife smuggling her pet cat out of country soon to become a warzone by sedating it and wearing it as a stole around her neck on the aeroplane. My favourite ‘lesson’ is the one about discovering how best to administer Vitamin A to children to prevent blindness. I feel, however, that this rather short book is a bit too light for its content.