While out on their mission delivering letters warning allied nations of the Demon Lord’s army, Usato and his companions save a young girl named Nea from zombies. Unbeknownst to them, however, is that it's all part of Nea's scheme to capture Usato, revealing her true nature as a necromancer. After a fierce battle, Nea unleashes a black dragon, forcing Usato and his companions to flee. As they try to escape, the dragon's poisonous sludge threatens to destroy everything in its path. Usato must confront the dragon, protect his friends, and stop Nea's evil plan. But as Usato confronts Nea, a familiar contract binds them together, and Nea joins the party! Now, Usato, Aruku, and Amako must navigate their journey with a former enemy in tow. Will they be able to trust Nea, or will her presence lead to even more danger? Perfect for fans of isekai adventures, magical battles, and unlikely friendships!