The Boke of Gostely Grace is a Middle English translation of the Liber specialis gratiae by the German visionary Mechthild of Hackeborn (1241–1298), a Benedictine/Cistercian nun at the convent of Helfta. This new Companion will add momentum to the current interdisciplinary and theoretical debate surrounding Latin texts and their translations into the vernacular, including a number of issues regarding women’s literary culture. It complements and supplements the new critical edition of the text, The Boke of Gostely Grace, edited by Naoë Kukita Yoshikawa and Anne Mouron with Mark Atherton, published by Liverpool University Press in 2022. A comprehensive introduction is followed by three parts. Part 1 examines vernacular translations of the Liber specialis gratiae from the late medieval and early modern periods in German, Dutch, Swedish, Italian and French. Part 2 explores a wide-range of critical issues in The Boke of Gostely Grace, and in particular aspects of the spirituality of Helfta. The volume concludes in Part 3 with aspects of the Last Things at Helfta, more specifically purgatorial piety and the theme of the dying and the dead. The volume as a whole provides a new and nuanced understanding of how the mystical literary output of Helfta circulated and was received in the late medieval literary culture of England and Europe.