In this work Ofer Hadass seeks to make sense of the eclectic outlook displayed by the Buckinghamshire cleric, astrologer and physician, Richard Napier (1559–1634). A vast quantity of manuscript material relating to Napier survives, partly in the collection of Elias Ashmole in the Bodleian Library and partly in that of Sir Hans Sloane in the British Library, and use has already been made of this by Michael MacDonald in his classic study, Mystical Bedlam (1981), by Ronald Sawyer in an unpublished doctoral dissertation and by Lauren Kassell in her study of Napier's mentor, Simon Forman. But what is distinctive about Hadass's book is the intensive attention that he has given to the actual detail of Napier's astrological medical practice and to the rationale both of this and of his ideas on related topics, including religion. The book opens with a careful exposition of the methods of diagnosis that Napier used, stressing their complexity and providing a lucid – if at times slightly laboured – account of the astrological and therapeutic principles on which they were based. We then move to a chapter on Napier's use of sigils, a key part of his practice, where Napier's own reticence in spelling out the rationale of his procedures is compensated for by an account of the views on related matters of thinkers from Aquinas to Ficino, and of notes on making sigils by Forman and Ashmole. More intriguingly, chapter iii deals with the advice that Napier was said to receive on medical and other matters from the Archangel Raphael, denoted in Napier's manuscripts as ‘Responsum Raphaelis’, and here a lucid account is given of early modern angelic communication, including its dangers, and of the changing views of it that occurred in the century and a half following Napier's death. Lastly, chapter iv expounds Napier's religious outlook, where Hadass finds an eclecticism which mirrors that in evidence in his ideas on medical and related topics, enabling him in a conclusion to stress the overall consistency of Napier's approach to the various matters with which he was concerned. Though brief, the book is illuminating and effective, making a learned and worthwhile contribution to our understanding of early modern magic and its religious milieu.