Fifteen-year-old orphaned Sab-ra lives in the valley of Talin high in the eastern Mountains. Her People guard a blue diamond mine hidden above Talin in the mysterious Skygrass Valley. Brutal Kosi Warriors are kidnapping Talin's young women because their tribe's birthrate as fallen to an unacceptably low level. The Kosi need more children to become warriors. Talin's Elders train their children as spies to warn them of Kosi raids. They send Sab-ra to poison the Warriors, but the mission goes awry and the Kosi kill her spy young partner. Blaming Sab-ra, the Elders banish her to Maidenstone, a school located in the ancient city of Namché where she nurses her grievances and plans revenge. After learning the skill of mind reading, Sab-ra works with a Priestess who can see the future. She teaches Sab-ra to scry and they witness an invading Army coming to Namché. Sab-ra meets Captain Grieg, head of the invading force and his translator, Justyn. Grieg's military objective is to locate and plunder the diamond mine. He becomes obsessed with Sab-ra and plans to torture her into revealing the location. Sab-ra escapes and ascends the mountain to warn her people of the threat. Justyn, who has fallen in love with her, follows. He lets her know Grieg has sent soldiers on their trail. Desperate to escape the troops, Sab-ra stumbles into the Kosi King's citadel. To her dismay, Sab-ra finds herself incredibly attracted to the Kosi King and longs to experience his ancient culture. She also learns her Elders taught her many lies about the Kosi. Sab-ra must persuade her People to hire the Kosi warriors to defend the Skygrass Valley from the anticipated Army attack. They travel to Natil, the seat of power for the valley People, to inform King Ruisenor of the threat. At Sab-ra's insistence, King Ruisenor agrees to hire the Kosi and together they negotiate a Peace Accord. When the Army attacks Skygrass, the Kosi are victorious, but sadistic Captain Grieg takes Sab-ra prisoner. After long days in the interior caves of the mountains, she escapes and marries the Warrior King. The morning after their wedding night, a volcanic avalanche destroys the mystic Skygrass valley. Sab-ra survives but the Kosi King is missing and Grieg is very much alive. Sab-ra stands between two warring cultures, two men who love her and a man who seeks her death. How Sab-ra resolves this dilemma makes for non-stop action. In the end, Sab-ra is able to achieve her dream of peace by giftedness, grace and diplomacy, but she must pay a terrible price. Sab-ra's husband is presumed dead. She faces pregnancy and her future alone in the winter snows.