For the past two hundred years, the demon sword Asperides has led a quiet life. While his physical form has been tasked with guarding the body of an evil sorcerer, the rest of his consciousness has taken a well-earned vacation. Nack Furnival, on the other hand, is far from satisfied with his existence. Nack has trained since birth to be a brave and noble knight—but, unfortunately, he isn’t especially good at it. Determined to prove his worth, Nack needs a quest. And to complete that quest, he’ll need the one thing no knight can do without: a sword. When an attempt to resurrect the evil sorcerer throws Asperides into Nack’s path, the demon sword can’t help but trick the boy into making a contract to become his new owner. And with the newly undead (and very, very angry) sorcerer on their trail, Asperides and Nack find themselves swept up in a bigger adventure than either of them bargained for: saving the world.