Four mercenaries are thrust into a conflict as warring nations try to steal the temples of Erindarus. Their powers are unmatched on the field by any soldier or mage of the factions of Mer sula Monde. The cost of these powers is a mystery that only their handler, the professor knows. They know that it came at great price, but is it more than they are more than they willing to pay for in the end?
With their two associates, a pair of star-crossed lovers and a commander with a shadowy past, they strive to prove that they are just as human as the rest if a little bent on madness. With an unshakable resolve and the hidden motives of those in high places, they are sent across the lands as the last ditch effort to bring things into equilibrium with no conscience to follow, but the orders of the professor that had created them.
As the world reaches the precipice of the abyss that holds it together, they are met with an unshakable realization, that the last notes that are heard will most likely be there own.
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.