The story follows the war between the Empire of Lassania and the Dalvani Magocracy. The empire is governed by a matriarchal royal family of dragonmaidens, the Vashtal, that uses its taming of dread unwinged dragons to expand westwards over the Verdant Greens and Everguardian Mountains and meet with the desperate defenses of the Dalvani, a chaste-based mage society that presents an enormous resilience in being conquered.
Two threads are followed in this war: General Vaila Vashtal and her dragon Melthrax advancing with their Legions, facing trials of battle and the dangers of dragon Taming, against the mage Alduin, a young and afraid mage who is taken to the warfront because of his predilections for a specific capacity in magicking.
To the east, in the capital city of the Lassania Empire, Valsrest, an orphan by the name Scrappy discovers more about her ancestrality while becoming a capable thief. She will cross paths with the slave Ominira Odwá, an Indwomani from conquered lands who is unsure about his fate and purpose under the hands of the Empire, seeking his freedom and revenge.
In the epic conclusion to the Devil's Deal series, Freya has one final chance to discover the full potential of her own power, and to use it to restore balance in the universe - once and for all. After the destruction caused by Roisin, Ferya and Torix come to terms with their losses and mistakes... And prepare for a final battle that will change everything.