Five years have passed since Will learned Mary's secret, and he is now 13. His undead parents' lessons grow ever more difficult, but Will manages to stick to it. One day, Blood gives him an assignment requiring him to escape from the ruins in the city. Will desperately tries to fight his way out, but an odd sensation of malice stops him. It turns out that malice was coming from an unexpected source.

The "God of Undeath" Stagnate's sudden appearance catches the three undead off-guard. Although his attempt to abduct Blood and Mary is interrupted by Gus, the black mist bursting from his chest leaves them no time to feel relieved. Will is unable to do anything as Stagnate says to him with a fearless smile, "It's all thanks to you."

Menel leads Will to a village that's being attacked by monsters. As he banishes them, he learns gravity of the tragedies caused by the attack. Piled-up bodies and burnt houses are everywhere. Then, from their midst, a faint voice catches Menel's attention. The voice belongs to a severely burnt young boy who has turned undead.

A look back at Will's experiences and travels thus far.

Will and his friends, who travel with Bee and Tonio, finally arrive at the target "City of White Sails (White Sails)". Will is impressed by the big city he sees for the first time and the people who live there. When healing the tiredness of his travels, the bell of an emergency rings. Looking out in a hurry, a big black shadow crosses over their heads--

Will, who was appointed as a paladin, was responsible for the reconstruction of the village and the extermination of demons. One day, he goes to "Beast Woods" with Reistov and Menel, who have two names, "Tsuranuki", in order to search for a unit that does not return. He feels something is wrong with the scattered bodies and proceeds to the valley in the back ...