This is a bigger and richer book than might at first be expected. It is not a biography of Peter Heylyn, although it does tell us interesting and significant things about his family and his relationships with those in positions of influence. It sets out, instead, to answer the question, ‘Where do Laudians come from?’ and explores what this particular Laudian believed. Milton describes Heylyn as a ‘government hit man’ and as a ‘spokesman’ for the Laudian movement. Heylyn's polemical and occasionally poisonous pen wrote on all the significant topics that Laudians contested from the 1620s into the early days of the Restoration. Milton skilfully guides us through some famous theological battles and provides a sophisticated account of how Heylyn's own views shifted and developed. He also identifies the beliefs that united Heylyn with other Laudians and the opinions that divided them. By the end of the book we have been given a careful analysis of the ‘fluid’ character of the whole Laudian movement. Milton's account of what Heylyn had to say about the Reformation and about continental Protestantism significantly advances understanding of the arguments that were of the essence in the early seventeenth century. Milton also offers a nuanced reading of Heylyn's complex royalist and clerical beliefs. As a bonus, there is a fascinating glimpse of the competition for patronage during the Personal Rule and the life of a Laudian minister during the Commonwealth. Milton knows, of course, that he is dealing with polemic. He spots the inconsistencies and the occasional carelessness of Helylyn's passionate indignation. He does not make it all too tidy. It is deeply ironic that Peter Heylyn should claim the attention of a scholar who has such reverence for accuracy and evidence. It makes for a very good book.