1171 AD, Orkney Islands, 8 miles north of Scotland.
Almost twenty years have passed since we first met Eilidh and Torleik from Book II, who are now parents of six, including protagonist Vor. Torleik's horse breeding business on the island of Meginland in the Orkneys is thriving. Vor loves working with the horses, but she wants to participate in something that is larger than her, to be a part improving the lives of females by teaching them reading, a skill begun by her female MacAoidh ancestors. The only problem: to be "chosen by the Goddess" and given a specific charge, she would have received a spiral birthmark on her neck at birth. Her older sister, Aila, who was born with the spiral, wants nothing to do with the charge, which involves a mystical Druid book that has magically disappeared.
Vor worries about the Goddess's warning for those who do not complete her charge. Will her father's business dry up and disappear? When Vor and her elder sister are overheard having a conversation regarding her father's horse-breeding business and the appearance of slave trade activity in the sea caves attached to her father's property, someone notifies the authorities. Her father is arrested and held for questioning, and his assets are frozen while her parents are planning her sister's wedding to Frenchman, Armand LaVelle.
Avid horseman, Louis, King of France, gets wind of the race and changes the venue from Scotland to France, and invites the family to have the wedding in France. He even offers a special allowance to ease the family's finances. A horse race will follow the wedding, and there will be only two horses and two female riders-Vor and her father's horse, Fillian, and a pale ivory horse named Ivor, ridden by an outspoken, brash woman named Vivi. Vor, an excellent horsewoman, has a disturbing vision of her and her father's horses all drowning, so doesn't want to sail to France for a race. But she soon learns that is the only way to win the prize that will pull her father out of debt, and her, back into his good graces.
Along the way, she becomes friends with the exasperating Vivi, and exerciser/trainer, Luc, a mysterious nomad who appreciates Vor's goal to attend The Sorbonne. Vor doesn't mind pleasant sea-faring pirates willing to transport them on a faster ship with a larger cargo hold to transport the family's racehorse, Fillian.
But all is not as it should be. Someone is trying to poison Vivi. Vor begins to suspect Vivi's guardian, Gabriel, is trying to get rid of Vivi and replace her because Vivi knows too much about Gabriel's illegal business operations. But then, so does Vor. They must figure out what all the clues lead up to... before it's too late for all of them.
