The Mortal Contract follows Zarina and her immortal companion, Kivuli, as they leave the safety of their home island and explore the dangers of an industrially-evolving world. Their encounters with social unrest and political oppression lead them to question the nature of mortality and search for solutions to seemingly impossible dilemmas.

Across the ocean, the vindictive Absinthia and her brother, Talon, seek to corrupt the leaders of Morrigan and use their power to free a dark and ancient entity from his prison.