Morpheus Ravenna's devotional and scholarly study of the Morrígan — the Great Queen of Irish myth — drawing together the surviving textual sources, the archaeology, and a working devotional practice into a single volume.

It is among the most widely recommended titles on the Concrescent list, carrying a five-out-of-five average reader rating, and is frequently cited as a model for how Pagan scholarship and lived devotion can be written together rather than apart.

The book is published as both a paperback and a color casebound hardcover edition.