Theo Cornaro is a wandering knight whose Crest lets him drive back Chaos. He rescues the mage Siluca Meletes in the fallout of the Great Hall Tragedy, the peace ceremony where a Demon Lord materialized and killed the archdukes of both warring factions. Impressed by his goal of liberating his homeland, Siluca binds herself to Theo by magical contract, and the two set out to unite the fractured lords of the continent of Atlatan against the spreading Chaos.