Continuing the futuristic, outer-space adventures of young Nicole Oresme and her mad-scientist employer, Dr. Seamus O'Murchadha: Our protagonists visit the planet Mars, which its Sino-Japanese colonists call Huoxing, where Seamus must pay his respects to his late friend Po Xu-ke and deal with Po’s nefarious nephews. Along the way they meet the android/slave Ventura, formerly Po’s concubine, who has some secrets of her own. Later, our protagonists proceed to the planetoid Vesta, where they become involved in a murder mystery that is linked to a scheme which could result in the deaths of millions and an inter-planetary war.