Professor Darryl Hart has taken the plunge. A specialist in the history of twentieth-century American evangelicalism, especially Presbyterianism, he has a string of impressive publications to his credit such as Defending the Faith: J. Gresham Machen and the Crisis of Conservative Protestantism in Modern America (2003). He is an elder in the Orthodox Presbyterian Church, founded by Machen, and has written their denominational history. Now in this new book the good professor leaves his specialist subject behind and sets out to narrate the history of Calvinism, not just in America but across the continents, from its sixteenth-century origins to the present day. It is nothing less, as Hart himself tells us, than ‘an audacious undertaking’ (p. viii). Similar surveys are usually multi-authored, like Calvin and his Influence 1509-2009, edited by Irena Backus and Philip Benedict (OUP, 2011). Benedict’s massive and ground-breaking monograph, Christ’s Churches Purely Reformed: A Social History of Calvinism (Yale, 2002), stops at the end of the seventeenth century. But Hart bravely tackles half a millennium single-handedly. He freely acknowledges that as a result he is forced to make pronouncements on subjects and eras in which he has ‘no professional competency’, and diving into this terra incognita is ‘almost as scary as bungee jumping’ (p. viii). It is an apt image. As we rush through numerous scenes from Calvinism’s history, hurtling down the centuries on the end of a metaphorical bungee rope, it is easy to lose perspective. Important distinctions are blurred, details are mistaken, and major features are missed altogether.