Father Mark Wycliffe, a Roman Catholic priest and space engineer, flees from Earth's wars by serving aboard a Mars space station. Above Mars, he meets a mysterious woman who claims to be the Virgin Mary. He is skeptical of the vision; could it be an illusion created by asteroids called Siren Stones? Later, on the Moon, he meets Jessica, a teenage girl in a Catholic school uniform. Jessica loves to shop in the Moon's largest shopping mall and hang out in its coolest nightclub. But Jessica also claims to be Jesus and uses her special powers to start a nuclear Armageddon on the Moon and the Earth. Father Wycliffe, the Virgin Mary, scientists, and clergy must stop Jessica from carrying out her Father's will. While the mortals and her immaculate mother try to foil her, Jessica happily splurges on designer clothes, luxuries she never had in first century Judea.

The Moon Under Her Feet combines space opera, ghost story, and theology in a way seldom seen in science fiction and fantasy. It reveals both humor and tragedy as it traces the lives of its characters and their mission in space. It was a finalist for the 2008 Aurora Award for Best Long-Form Work in English. From Derwin Mak, multiple Prix Aurora Award winner (Canada's National Science Fiction Award) for Transubstantiation and The Dragon and the Stars.