Shipwrecked on the frozen seas of an ice world, in a future so distant that the only traces left of our time are shards of glass, fifteen year old twins, Jacob and Elya, are rescued by Aulf, the young mail man, who earns a precarious living sailing his small boat between the treacherous arms of the Vajra Crevasse, to deliver mail to the troubled islands of Hexult.
When the seas rose and the world froze, much technology was lost, and Jacob and Elya's superior knowledge of science leads the superstitious islanders to believe they are magicians. An ancient prophecy, predicting their arrival, spells trouble for the twins, and before long threatens their relationship with each other and puts and Elya's life in danger.
With the islands at each other's throats, Jacob and Elya come up with a revolutionary plan to help improve relations across Hexult, an idea instantly snapped up by Hexult's resident magician, Gabriel, who sees it as the perfect way to redeem his own fading glory, and immediately plots to undermine the twins' credibility and snatch the credit for himself.
With the help of Aulf, and his fiery crewmate, Ingar the Orphan, Jacob and Elya must overcome personal tragedy, the islanders' prejudice, marauding ice raiders, and Gabriel's vengeful scheming, in order to save their reputations and their lives.