This is a big book about an even bigger book. Thomas Edwards’s Gangraena has featured in many works on the English Revolution, but this is the first full-length study devoted to the book in all its facets. As such it is very welcome. Gangraena is often cited in one or both of two closely related ways: as an expression of Presbyterian fears during the mid- and late 1640s and as a source for stories that illustrate Independent and sectarian excesses in this period—soldiers urinating into fonts or baptizing cats and horses, for example. The great merit of Ann Hughes’s book is that it locates Gangraena within a rich variety of different contexts and approaches it from a wide range of perspectives. Hughes draws on important recent developments in the history of the book and the press, the nature of popular religion, and the reception of reading material. She looks at both Edwards and his readers, at how his book came to be written and published, at the sources that it drew on, at the impact that it had at the time, and at how it has been perceived since. In other words, she offers a kind of “histoire totale” of one particular, highly significant, book. It is a fascinating and fruitful exercise.