Scholars have long sought to evaluate Luther's competence in Hebrew, and to identify the various means by which he attained it. In this rich and deeply insightful volume, Andrew Niggemann pushes the discussion into important new areas by examining the impact of Luther's knowledge of Hebrew on his biblical exegesis. He does this through a detailed examination of Luther's translation of the Twelve Minor Prophets, the final part of his Old Testament (the translation itself was completed in 1532, hence the ‘mid-career’ of the book's title). These books thus contain Luther's most fully developed thought; moreover, the hundreds of annotations commenting on the Hebrew text provide ample evidence for understanding his approach. After a first chapter which provides the historical and historiographical context and reviews the main sources (the translation is set against his lectures and commentaries on the same books), four substantive chapters deal with a series of ‘exemplary aspects’ of Luther's use of Hebrew. Chapter ii is concerned with difficult passages in the Hebrew text, and demonstrates that Luther was not as consistent in rendering them into colloquial German as he repeatedly claimed. In the next chapter, Niggemann examines how Luther sought to replicate the intensity of the Hebrew in his German translation, particularly with regard to the concept of Anfechtung (‘anguish’). Chapter iv looks at Luther's use of cross-references as a means of understanding how he sought to use the Bible to interpret itself. The final chapter considers the role that Luther's use of mystical language and concepts played in shaping his translation. This book is based on Niggemann's prize-winning 2018 Cambridge doctoral dissertation, and there are still some echoes of those origins. Each of the substantive chapters is focused around a set of carefully chosen examples which are subjected to close and systematic discussion. Perhaps inevitably, this leads to a degree of repetition, as the same fundamental points are made repeatedly in the individual chapters. These passages, and many more, are gathered together in almost 120 pages’ worth of appendices. None the less, what Niggemann has achieved here is substantial. He has greatly enhanced our appreciation of the nature and significance of Luther's engagement with the Hebrew language and traditions. Luther was, he suggests, an ‘amateur translator’, but still reflected fully and thoughtfully on the language. This in turn adds an important dimension to our understanding of Luther as a biblical exegete. As Niggemann demonstrates, many of Luther's linguistic reflections had consequences for his theology. More broadly still, this study provides further evidence that modern scholarship is only beginning to appreciate the extent and significance of the Hebraic contribution to early modern culture and thought. In so doing, it demonstrates that there is considerable scope for future study, both in relation to Luther specifically, and to those who worked on Hebraic materials more broadly. In sum, this is a very impressive book, the significance of which must be properly assimilated into our appreciation of Luther and indeed the biblical scholarship of the Reformation era.