“This book wonderfully proves the value of collaborative research. The introduction describes how this collaboration came about and is by itself a little masterpiece. Like a detective story, it chronicles how the researchers gradually came to recognize that the Haggadah and its Latin—and very Christian—preface constitute one of the most remarkable testimonies in both image and word of the complex character of Jewish-Christian relations in the fifteenth century. Yet the manuscript, even after the collaborators’ fascinating findings, remains enigmatic and indeed mysterious. This is simply an extraordinary book about an extraordinary artifact.”—William Jordan, Princeton University