Petal on a Black Bough could be classified as a historical fantasy. A fusion of near-memoir, fiction and Celtic mythology, it represents a unique kind of story-telling for an American writer.

This book presents the reality of World War I to the start of World War II, a period that includes the Irish struggle for independence. The mythological warrior-goddess Medb (Maeve) known for sorcery, licentiousness, and affinity for war, emerges from the past to seek warriors who will help with Ireland’s independence. Her powers also enable her to shape shift, change ages, and migrate through space and time....

We meet Philip, a soldier in a French hospital for the wounded; Medb's heir, Maeve Dwyer, to whom Medb has given her spirit; Maeve’s artist lover Matthew; her father Patrick, who smuggles guns to the Irish...

The irony of the conversion from Medb to Maeve Dwyer affirms the futility of war and the necessity of love and peace.