When I first undertook the study of the Popish Plot the late Lord Acton wrote to me: "There are three quite unravelled mysteries: - what was going on between Coleman and Pere la Chaize; how Oates got hold of the wrong story; and who killed Godfrey." The following book is an attempt to answer these questions and to elucidate points of obscurity connected with them.<br><br>In the course of the work I have received much kind help from Dr. Jackson and Mr. Stanley Leathes of this college, from the Rev. J. N. Figgis of St. Catharine's College, and from my father; and Mr. C. H. Firth of All Souls' College has been exceedingly generous in giving the assistance of his invaluable learning and experience to a novice attacking problems which have been left too long untouched by those better fitted for the task.<br><br>It is only as a mark of the deep gratitude I bear him that I have ventured to dedicate this book to the memory of the illustrious man whose death has deprived it of its sternest critic. Few can know so well as myself how far its attainment falls short of the standard which he set up. With that standard before me I can justify myself only by the thought that I have tried to follow strictly the injunction: Nothing extenuate, nor set down aught in malice.