E.X. Ferrars was one of the most popular and prolific British crime writers of the twentieth century. This literary companion is designed to introduce readers to the full range of possibilities inherent in E.X. Ferrars's canon, connecting novels and short stories that share themes and strategies, and providing biographical data that yield insights into Ferrars's interests and concerns. A brief biography is included, as well as explanations of relevant genre terminology. This work is a pathway to better understanding this popular writer, whose work spanned 63 years and who, when she died at age 88, was at work on another mystery for her broad readership.